Spermatogenesis in horses is the process by which spermatozoa are produced in the testes. This complex sequence of events involves the proliferation and differentiation of germ cells, supported by Sertoli cells and influenced by hormonal regulation. Key stages include spermatogonial mitosis, meiosis, and spermiogenesis, resulting in the formation of mature sperm cells. Hormones such as testosterone and follicle-stimulating hormone (FSH) are integral to regulating this process. This topic encompasses research studies and scholarly articles that explore the mechanisms, hormonal influences, and factors affecting spermatogenesis in horses, as well as its implications for equine reproduction and breeding management.
Pagl R, Aurich C, Kankofer M.Activity of the anti-oxidative enzymes glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT), content of thiobarbituric acid reactive substances (TBARS) and SH-groups were determined in native stallion semen (n = 8 stallions). Semen was then diluted in Kenney extender, EquiPro((R)) extender either with or without addition of N-acetyl cysteine or phosphate-buffered saline (PBS) and stored for 72 h at 5 degrees C. Correlations between initial activity of enzymes and development of semen motility and membrane integrity were calculated. Activities of GSH-Px, SOD and CAT im...
Akcay E, Reilas T, Andersson M, Katila T.This study aimed to evaluate stallion sperm survival after 24 h of cooled storage in the presence of seminal plasma (SP) derived from the sperm-rich fractions (SRF) or sperm-poor fractions(SPF) of the ejaculate, without SP, or in the presence of SP from other stallions. Ejaculates were collected from four stallions using an automated phantom, which separated the semen into five cups. Centrifuged and washed spermatozoa from cup 2 (SRF) were mixed with skim milk extender to a concentration of 100 x 10(6) sperm/ml and then 1:1 (v/v) with SP from the stallion's own or another stallions' second (SP...
López ML, Olea N, Retamal CA.Freeze-fracture replicas of stallion spermatozoa, collected from the proximal caput, corpus and cauda epididymides regions, were analyzed by electron microscopy to explore the distribution and density of intramembrane particles (IMP). Conspicuous differences in density and arrangement of the IMP were observed in the different topographical domains of mature and immature spermatozoa. A reduction of IMP, especially remarkable in the post-acrosomal domain, was observed in mature epididymal spermatozoa when compared with samples collected from ductuli efferentes. Some structural species-specific d...
Sabeur K, Ball BA.Carbohydrate-binding proteins are thought to be involved in a myriad of sperm functions including sperm-oviductal and sperm-zona interactions. Recent studies in our laboratory have characterized galactose-binding proteins on equine spermatozoa as possible candidate molecules for sperm adhesion to oviduct epithelial cells. In the current study, equine sperm membrane proteins were subjected to galactose-affinity chromatography, and bound proteins were eluted with excess galactose in a calcium-free buffer. The eluted fraction recovered after galactose-affinity chromatography was used for generati...
Staempfli S, Janett F, Burger D, Kündig H, Imboden I, Hässig M, Thun R.In this study, the effect of exercise (treadmill, riding) on scrotal surface temperature (SST) in the stallion with and without suspensory was evaluated. Experiments were carried out between September and November 2004 using 12 Franches-Montagnes stallions from the National Stud in Avenches (Switzerland). Each stallion performed a standardized incremental treadmill and a ridden test with and without suspensory. The intensity of exercise was monitored by heart rate and blood lactate concentration. For SST measurements, special thermistors were developed and affixed to the most ventral part of t...
Rathi R, Honaramooz A, Zeng W, Turner R, Dobrinski I.Grafting of testis tissue from immature animals to immunodeficient mice results in complete spermatogenesis, albeit with varying efficiency in different species. The objectives of this study were to investigate if grafting of horse testis tissue would result in spermatogenesis, and to assess the effect of exogenous gonadotropins on xenograft development. Small fragments of testis tissue from 7 colts (2 week to 4 years of age) were grafted under the back skin of castrated male immunodeficient mice. For 2 donor animals, half of the mice were treated with gonadotropins. Xenografts were analyzed a...
Johnson L, Blanchard TL, Varner DD, Scrutchfield WL.Spermatogenesis is a process of division and differentiation by which spermatozoa are produced in seminiferous tubules. Seminiferous tubules are composed of somatic cells (myoid cells and Sertoli cells) and germ cells (spermatogonia, spermatocytes, and spermatids). Activities of these three germ cells divide spermatogenesis into spermatocytogenesis, meiosis, and spermiogenesis, respectively. Spermatocytogenesis involves mitotic cell division to increase the yield of spermatogenesis and to produce stem cells and primary spermatocytes. Meiosis involves duplication and exchange of genetic materia...
Vizcarra JA, Ford JJ.The sperm mobility assay used in the present study measures the rate of sperm penetration in a biologically inert cell-separation solution (Accudenz). When a sample of sperm is overlaid in a cuvette containing Accudenz, sperm penetrate the solution and absorbance of the sample can be measured with a spectrophotometer. This assay has been successfully used to select chicken and turkey semen donors. We validated this assay for semen from boars and stallions. Absorbance was measured after overlaying fresh semen from each species in prefilled cuvettes for 1, 5, 10, 15, 20, and 40 min. There were n...
Parlevliet JM, Pearl CA, Hess MF, Famula TR, Roser JF.The presence of steroids and their receptors throughout development, specifically androgen receptor (AR), estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta), in the epididymis of a high estrogen producing species like the stallion has not been determined. Epididymal and testicular samples were collected for analysis of testosterone and estradiol-17beta (E(2)) concentrations and for immunolocalization of AR, ERalpha and ERbeta. The concentration of testosterone in the testis and epididymis were not different among age groups (P>0.05). AR was localized in the principal cell...
Dias GM, Retamal CA, Tobella L, Arnholdt AC, López ML.'The highly packed chromatin of mature spermatozoa results from replacement of somatic-like histones by highly basic arginine- and cysteine-rich protamines during spermatogenesis, with additional conformational changes in chromatin structure during epididymal transit. The objective of the present study was to compare the nuclear characteristics of immature and mature epididymal stallion spermatozoa, using a variety of experimental approaches. Resistance to in vitro decondensation of chromatin, following exposure to SDS-DTT and alkaline thioglycolate, increased significantly in mature spermatoz...
Pesch S, Bergmann M, Bostedt H.Seminal plasma is very important for sperm metabolism as well as sperm function and survival and transport in the female genital tract. Analysis of enzyme activities and concentrations of elements can estimate integrity and function of sperm cell membranes. In man much data are available about biochemical analyses of seminal plasma. However, not many studies have been conducted in horses yet. We collected ejaculates from 72 stallions, measured the volume, obtained seminal plasma by centrifugation and examined spermatozoa with light microscopy for motility, concentration, for dead sperm and mor...
Sinnemaa L, Järvimaa T, Lehmonen N, Mäkelä O, Reilas T, Sankari S, Katila T.The effect of artificial insemination (AI) volume on uterine contractility and inflammation and on elimination of semen in the reproductive tract of mares was examined for 4 h after AI using two methods, scintigraphy and ultrasonography. The same doses were used in both methods: 2 and 100 ml of skim milk-extended frozen semen. In the scintigraphic study, the number of reproductively normal mares was four per group and in the ultrasonographic study five per group. For scintigraphy, the semen was radiolabelled with technetium-99m. The static scintigrams were acquired immediately before and 30, 6...
Staempfli S, Janett F, Burger D, Kuendig H, Haessig M, Thun R.In this study the effect of exercise (treadmill, riding) on scrotal surface temperature (SST) in the stallion with and without suspensory was evaluated. Our results show that SST was significantly influenced by exercise and suspensory the latter causing in general a rise in SST. Furthermore, from SST measurements in stallions exercised on treadmill and by riding, it is concluded that air circulation near the scrotum must be considered an important thermoregulatory factor.
Schambony A, Hess O, Gentzel M, Töpfer-Petersen E.Cysteine rich secretory proteins (CRISPs) have been detected immunochemically in the equine male genital tract. CRISPs are secretory products of the epididymis, the ampulla and the seminal vesicle. A particular feature of the horse is the abundance of CRISPs in seminal plasma. CRISPs can also be detected in extracts of testicular, epididymal and ejaculated spermatozoa in increasing amounts. Unlike other seminal plasma proteins, they cannot be removed completely from spermatozoa by high salt treatment. The remaining CRISP antigens are localized on the midpiece, and the postacrosomal and equator...
Shakeel M, Jung H, Yoon D, Yoon M.The economic impacts of infertility and subfertility of stallions greatly influence the horse breeding industry. Self-renewal and differentiation of spermatogonial stem cells are the initial processes to maintain an adequate sperm population. Thus, understanding these processes may provide useful information to reveal the causes and remedies of subfertile and infertile stallions. Stallions are seasonal breeders. About 50% of the sperm population is reduced during the non-breeding season (NBS) in stallions. The seasonal regulation of spermatogenesis renders stallions as ideal models to understa...
Ghallab ARM, Abou-Ahmed MM, Fad AM, El-Badry DA, Shahat AM, Moawad AR.Cryopreservation of Arabian stallion semen is important in order to improve the function and fertility of frozen/thawed semen in this breed. Objective: To investigate the effects of centrifugation, type of semen extenders, and type of cryoprotectants on the quality of frozen/thawed Arabian stallion spermatozoa. Methods: Semen samples collected from four adult Arabian stallions (one ejaculate per week for 10 consecutive weeks) were either processed directly without centrifugation (no centrifugation; NC) or subjected to centrifugation on the gel-free fraction. Centrifugation protocols were divid...
Mawyer JD, Cavinder CA, Vogelsang MM, Sigler DH, Love CC, Brinsko SP, Blanchard TL, Varner DD, Arnold CE, Teague S, Gordon RK.Stallions (n = 8) were implanted with a thermal sensory device in the muscle of the neck and the subcutaneous tissue of the scrotum and then assigned to either a nonexercise (Non-EX; n = 4) or exercise (EX; n = 4) group. A motorized equine exerciser was used to work EX stallions 30 min/d for 4 d/wk during a 12-wk period from July through October 2010. Temperatures (subcutaneous scrotal, intramuscular neck, and rectal) were recorded at 0, 22, and 30 min after the start of exercise, as well as 60 and 120 min post-exercise. Hourly ambient temperature and relative humidity data were also obtained....
Clay CM, Clay JN.The seasonal reproductive cycle of stallions is characterized by an annual regression and recrudescence in testicular function and concentrations of LH, FSH, and testosterone in serum. Maximum reproductive capacity occurs during the increasing day lengths of spring and summer. The annual cycle in LH secretion may reflect a seasonally associated and photosensitive reduction and replenishment in pituitary content of LH. Similar to other seasonal breeders, it appears that stallions may possess an endogenous circannual rhythm in reproductive function that is subject to manipulation by altering the...
Podico G, Ellerbrock RE, Curcio BR, Cheong SH, Lima FS, Canisso IF.Urospermia is a major ejaculatory dysfunction affecting stallions. It has been thought that urine-contaminated semen should not be cryopreserved; however, on select cases, urine contamination of semen cannot be avoided. A recent study suggested that urospermic semen can be cryopreserved after cushion centrifugation and extension. Thus, this study aimed to assess the use of single-layer colloid centrifugation (SLC) to process frozen-thawed urine-contaminated stallion semen. Raw ejaculates (n = 55) from eight stallions were split into three groups: no urine, low (20%), or high (50%) urine conta...
Fernández-Hernández P, Marinaro F, Sánchez-Calabuig MJ, García-Marín LJ, Bragado MJ, González-Fernández L, Macías-García B.Equine fertilization cannot be performed in the laboratory as equine spermatozoa do not cross the oocyte's zona pellucida . Hence, a more profound study of equine oviductal fluid (OF) composition at the pre-ovulatory and post-ovulatory stages could help in understanding what components are required to achieve fertilization in horses. Our work aimed to elucidate the proteomic composition of equine OF at both stages. To do this, OF was obtained postmortem from oviducts of slaughtered mares ipsilateral to a pre-ovulatory follicle ( = 4) or a recent ovulation ( = 4); the samples were kept at -80°...
This Opinion piece is offered as a cursory overview of sperm development, function, and transport through the eyes of an equine veterinarian. My professional background is predominantly clinical in nature, but my fascination with sperm function and preservation has led to a fairly sizeable review of the scientific literature over the years in hopes of extracting laboratory findings that have application to my daily activities in the clinical arena. Spermatozoa are quite unique among cellular types with regard to both form and function, and represent the only endogenously derived cell type that...
Lindeberg H, Karjalainen H, Koskinen E, Katila T.A study was performed to test a new semen collection device (Equidame phantom) that fractionates the ejaculate by comparing the quality of semen obtained by the Equidame phantom with that obtained by a Missouri artificial vagina. Semen from 4 Finnhorse stallions was collected 4 times per stallion by both methods. Half of the ejaculate was frozen and the other half extended and loaded into 2 Equitainer transport containers (24- and 48-h samples). Motility parameters were determined by a Hamilton-Thorn motility analyzer after cooled storage for 24 and 48 h and again after freezing/thawing. Raw a...
Al-Khaldi K, Yimer N, Al-Bulushi S, Haron AW, Hiew M, Babji AS.The aim of this study was to evaluate the effects of adding different concentrations of edible bird's nest (EBN) which is secreted by swiftlet birds (), into EquiPlus® and E-Z Mixin® extenders on the quality of chilled Arabian stallion semen at various storage times (0, 24 and 48 h). Ten ejaculates were collected from five stallions, and diluted using the two extenders containing 0% (control), 0.12%, 0.24% and 0.24% of EBN + seminal plasma (SP). All the diluted semen samples were then cooled and stored at 5 °C, and examined at 0, 24 and 48 h. Sperm kinetic parameters were assessed using com...
Ferrer MS, Miller LMJ.Antisperm antibodies (ASAs) have been associated with infertility in stallions. The objectives of this study were to investigate the frequency of ASA-positive semen samples in satisfactory and non-satisfactory breeder stallions, the association between ASA binding and semen quality, and factors that may affect the diagnosis. Breeding soundness examinations were performed in 21 stallions and the percentage of IgG- and IgA-bound spermatozoa was evaluated using flow cytometry. Median IgG and IgA binding did not differ between the first and second ejaculates. The percentage of IgA-bound spermatozo...
Bucci D, Spinaci M, Mislei B, Gadani B, Rizzato G, Love CC, Tamanini C, Galeati G, Mari G.Stallion semen storage for artificial insemination is mainly based on liquid cooled storage. In many stallions this technique maintains sperm quality for an extended period of time (24-72 hr) at 7°C. While this technique is commonly used in the horse industry, there can be a decline in fertility in some stallions, due to an inability of their sperm to tolerate the cool storage process. The aim of the present work was to evaluate the effect of two natural antioxidants (epigallocatechin-3-gallate (EGCG) at 20, 60 and 120 μm and green tea polyphenols, and p at .001, .01 and .1 mg/ml) on some...
Alghamdi AS, Troedsson MH, Xue JL, Crabo BG.To compare the effect of semen extender and seminal plasma on postthaw motility and filtration through a glass wool-Sephadex (GWS) filter for frozen stallion semen. Methods: 7 stallions from which we collected > or = 3 ejaculates/stallion. Methods: 4 experiments were conducted to evaluate postthaw quality of frozen stallion semen. Kenney extender was compared with glucose-EDTA extender by use of various dilution rates that resulted in differing concentrations of seminal plasma. Stallions known to produce semen with poor postthaw quality were used to investigate whether a particular extender or...
Smits K, Hoogewijs M, Woelders H, Daels P, Van Soom A.Many wild equids are at present endangered in the wild. Concurrently, increased mechanization has pushed back the numbers of some old native horse breeds to levels that are no longer compatible with survival of the breed. Strong concerns arose in the last decade to preserve animal biodiversity, including that of rare horse breeds. Genome Resource Banking refers to the cryostorage of genetic material and is an approach for ex situ conservation, which should be applied in combination with in situ conservation programmes. In this review, we propose that, owing to the great reproductive similarity...
Ing NH, Brinsko SP, Curley KO, Forrest DW, Love CC, Hinrichs K, Vogelsang MM, Varner DD, Welsh TH.Testicular steroidogenesis and spermatogenesis are negatively impacted by stress-related hormones such as glucocorticoids. The effects of two injections of a therapeutic dose of dexamethasone (a synthetic glucocorticoid, 0.1mg/kg; i.v.) given 24h apart to each of three stallions were investigated and compared to three saline-injected control stallions. Dexamethasone decreased circulating concentrations of cortisol by 50% at 24h after the initial injection. Serum testosterone decreased by a maximum of 94% from 4 to 20h after the initial injection of dexamethasone. Semen parameters of the dexame...
Johnson L, Carter GK, Varner DD, Taylor TS, Blanchard TL, Rembert MS.The number of Sertoli cells is important in spermatogenesis as noted by significant correlations between the number of Sertoli cells and the number of germ cells observed as early as type B2 spermatogonia in the horse. However, the stage within spermatocytogenesis at which these relationships first occur is unclear. The relationships between the number of Sertoli cells and parenchymal weight and the number of germ cells during the mitosis of spermatogenesis were determined in 184 adult horses to identify the developmental stage (that is, the earliest germ cell) at which significant relationshi...
Amann RP, Thompson DL, Squires EL, Pickett BW.Extragonadal reserves totalled 89 X 10(9) spermatozoa for 5--16-year-old sexually rested stallions and 60 X 10(9) for 2--4-year-olds. Regardless of age, the cauda epididymidis contained 62% of the total reserves and the vas deferens, including the ampulla, contained 7% of the total reserves of spermatozoa. The caput plus corpus epididymidis from 5--16-year-old stallions (N = 41) contained 14.9 X 10(9) spermatozoa per side as compared (P less than 0.01) to 8.5 X 10(9) for 2--4-year olds (N = 30). Frequency of ejaculation did not influence the number of spermatozoa found in caput plus corpus epi...
Staempfli S, Janett F, Burger D, Kündig H, Imboden I, Hässig M, Thun R.In this study, the effect of exercise (treadmill, riding) on scrotal surface temperature (SST) in the stallion with and without suspensory was evaluated. Experiments were carried out between September and November 2004 using 12 Franches-Montagnes stallions from the National Stud in Avenches (Switzerland). Each stallion performed a standardized incremental treadmill and a ridden test with and without suspensory. The intensity of exercise was monitored by heart rate and blood lactate concentration. For SST measurements, special thermistors were developed and affixed to the most ventral part of t...
Herrera-Luna CV, Budik S, Helmreich M, Walter I, Aurich C.Glucocorticoids (GCs) as mediators of the stress response may affect Leydig cell function by inhibiting either luteinizing hormone receptor expression or testosterone biosynthesis. The isozymes 11β-hydroxysteroid dehydrogenase (11βHSD) 1 and 11βHSD2 control the intracellular cortisol levels. Little is known about the effects of stress on fertility in the equine. The objective of the present study was to determine the presence and cellular localization of glucocorticoid receptors (GCR) and glucocorticoid-metabolizing enzymes (11βHSD1 and 11βHSD2) in equine epididymal and testicular tissue ...
Da Silva-Álvarez E, Gaitskell-Phillips G, Ortiz-Rodríguez JM, Serres C, García-Rodríguez B, Gutiérrez-Cepeda L, Martín-Cano FE, Echegaray A....This study aimed to assess if Ecotext, a new software for evaluation of testicular echotexture, is a good method for diagnosis of stallions with testicular dysfunction (TD). Relationships between Ecotext parameters and sperm motility and production, testicular volume, and testicular blood flow were also studied. Ecotext provides a total of six echotexture parameters: Ecotext 1 (black pixels), 2 (white pixels) and 3 (grey pixels), and another 3 parameters related to hypoechogenic areas: Ecotext tubular density (ETD), Ecotext tubular diameter (ETd), and Ecotext tubular area (ETA). Stallions (n ...
Al-Jaru A, Goodwin W, Skidmore J, Khazanehdari K.Advances in molecular cytogenetics have provided the opportunity to study events during prophase I of meiosis. Immunofluorescent localization of different meiotic protein components were used to characterize the early stages of the first meiotic division in horse spermatocytes. The frequency and distribution of recombination events during prophase I were investigated using the mutL homolog 1 (MLH1) protein that is known to be associated with these events. The frequency and distribution of MLH1 foci were investigated in pachytene nuclei of 6 fertile stallions, and the average relative synaptone...
Roach J, Schnobrich M, Ellerbrock R, Feijo L, Bradecamp E, Alvarenga MA, Kline K, Canisso I.This study compares two methods for seminal plasma removal by evaluating sperm recovery rates, and motility and morphology of cooled-stored semen. Ejaculates were divided into three groups: control, filtration and cushioned centrifugation. Semen was extended to 25 million sperm/ml using a skim-milk-based extender and stored at 5°C for all groups. Sperm motility (total motility (%TM) and progressive motility (%PM)) was determined at 0, 24, 48 and 72 hours by a computer-assisted sperm analyser. Sperm morphology was assessed using differential interference microscopy. Overall, %TM of the cen...
Yu J, Wang Z, Wang F, Yang G, Cheng J, Ji C, Li M, Liu B, Wang Y, Dang R.Testicular development and spermatogenesis are tightly regulated by the number of genes and noncoding genes, and mRNAs and lncRNAs play vital roles in regulating posttranscriptional gene expression. However, mRNAs and lncRNAs have not been systematically identified in the testes of donkeys. In this study, mRNA and lncRNA expression profiles in the testes of DeZhou donkeys between 2 months and 2 years of age were comprehensively analysed by RNA sequencing. We identified 56,605 lncRNAs and 61,857 mRNAs by gene expression analysis, and 21,845 lncRNAs (p < .05) and 14,109 mRNAs (p < .0...
Giese A, Jude R, Kuiper H, Raudsepp T, Piumi F, Schambony A, Guérin G, Chowdhary BP, Distl O, Töpfer-Petersen E, Leeb T.The cysteine-rich secretory protein (CRISP) family consists of three members called acidic epididymal glycoprotein 1 (AEG1), AEG2, and testis-specific protein 1 (TPX1), which share 16 conserved cysteine residues at their C-termini. The CRISP proteins are primarily expressed in different sections of the male genital tract and are thought to mediate cell-cell interactions of male germ cells with other cells during sperm maturation or during fertilization. Therefore, their genes are of interest as candidate genes for inherited male fertility dysfunctions and as putative quantitative trait loci fo...
Lackey BR, Gray SL, Henricks DM.The multi-functional proteins, insulin-like growth factor-I (IGF-I) and leptin were present in seminal plasma from different species. Concentrations of IGF-I in equine and porcine semen were 20 and 17.5 ng/ml, respectively. Seminal plasma concentrations of leptin were 1 ng/ml in human and 11 ng/ml in porcine samples.
Munabi AK, Cassorla FG, D'Agata R, Albertson BD, Loriaux DL, Lipsett MB.Decreased sperm counts and impaired sperm motility are present in a substantial proportion of men with varicocele. Elevations in the temperature of the affected testis, and increased spermatic vein estradiol (E2) concentrations have been found in some of these patients. To investigate the possibility that increases in temperature lead to a pattern of testicular steroidogenesis that results in increased E2 synthesis, we have examined the effects of temperature changes on the activities of four important testicular steroidogenic enzymes. 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), 17-hydro...
Gottschalk M, Sieme H, Martinsson G, Distl O.A high quality of stallion semen is of particular importance for maximum reproductive efficiency. In the present study, we estimated the relationships among estimated breeding values (EBVs) of semen traits and EBVs for the paternal component of the pregnancy rate per estrus cycle (EBV-PAT) for 100 German Warmblood stallions using correlation and general linear model analyses. The most highly correlated sperm quality trait was total number of progressively motile sperm (r = 0.36). EBV-PAT was considered in three classes with stallions 1 SD below (<80), around (80-120), and above (>120) the popu...
Aitken RJ, Lambourne S, Medica AJ.A capacity to predict the likelihood of pregnancy following natural matings would be of considerable benefit to the Thoroughbred horse breeding industry. In this article, we describe a strategy for achieving this outcome through the analysis of dismount samples, that achieved an overall accuracy of 94.6%. The purpose of this study was to determine whether the analysis of dismount semen samples from Thoroughbred stallions could be used to predict whether a given mating would result in a pregnancy. The analysis was based on 143 matings of 141 mares by a cohort of 7 Thoroughbred stallions over a ...
Cinone M, Albrizio M, Guaricci AC, Lacitignola L, Desantis S.Heat shock proteins are the most evolutionarily conserved protein families induced by stressors including hyperthermia. In the context of pathologies of the male reproductive tract, cryptorchidism is the most common genital defect that compromises the reproductive potential of the male because it induces an increase in intratesticular temperature. In equine species, cryptorchidism affects almost 9 % of newborns and few studies have been carried out on the molecular aspects of the retained testis. In this study, the expression pattern of HSP60, 70, and 90 in abdominal and inguinal testes, in t...