Characterization and phylogenetic significance of rhinoceros luteinizing hormone beta (LHbeta) subunit messenger RNA structure, complementary DNA sequence and gene copy number.
Abstract: The luteinizing hormone (LH) beta subunit gene is expressed in the pituitary glands of all mammals, whereas the closely related chorionic gonadotropin (CG) beta subunit genes have been identified only in primates and equids, and are expressed in placenta. In the case of horses, there is a single-copy equine (e) luteinizing hormone/chorionic gonadotropin hormone beta subunit gene (eLH/CGbeta) that (1) is expressed in both pituitary gland and placenta, (2) encodes a characteristic carboxyl terminal peptide (CTP) extension, and (3) transcribes an atypically elongated 5'-untranslated region (UTR) in both pituitary and placenta. However, it is not known whether similar expression patterns and gene locus characteristics may be exhibited by other members of the order Perissodactyla (equid, rhinoceros and tapir species). To begin to investigate these possibilities, we undertook analysis of the rhinoceros (rn or rhino) LH/(CG?)beta gene locus and the rnLHbeta cDNA. Total RNA isolated from the pituitary gland of a female white rhino was used as template for amplifying rnLHbeta cDNA by reverse transcription-polymerase chain reaction. Following cloning of the amplified cDNA, nucleotide (nt) and deduced amino acid sequences were determined. The first in-frame stop codon occurred at codon position +122, suggesting that the rnLHbeta subunit does not contain a CTP. To assess gene copy number, Southern blot analysis of Indian rhino genomic DNA was performed. The resulting simple hybridization pattern indicated that, as in the horse and donkey, there is a single-copy gene at the rnLH/(CG?)beta gene locus. Primer extension mapping of the pituitary transcriptional start site of the rnLHbeta subunit gene revealed an 8 nt 5'-UTR which is similar to that reported for the majority of mammalian LHbeta transcripts. Northern analysis was consistent with the transcriptional start site findings. We postulate from these data that rhinos diverged from equids prior to the occurrence of the mutations causing CTP expression and adoption of a non-consensus 5'-UTR/proximal promoter region. However, these findings do not rule out the possibility of expression of a placental CGbeta subunit lacking a CTP in rhinos.
Publication Date: 1997-08-22 PubMed ID: 9305757DOI: 10.1016/s0378-1119(97)00080-2Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research aims to understand the structure of the luteinizing hormone beta (LHbeta) subunit gene in rhinoceros. The results suggest that rhinoceros have a single-copy gene for LHbeta, similar to horses and donkeys. It is suggested that rhinoceros may have diverged from equids prior to mutations which led to alterations in the gene’s expression and structure.
Objective of Research
- The main objective of the research was to investigate characteristics of the luteinizing hormone (LH) beta subunit gene in rhinoceros.
- The research aimed to understand the molecular characteristics of this gene, and compare them with known patterns in other members of Perissodactyla order namely horses (equids) and tapirs.
- Identifying these patterns could point towards historical evolutionary relationships.
Methodology
- The researchers used reverse transcription-polymerase chain reaction (RT-PCR) to amplify the LHbeta complementary DNA (cDNA) from isolated RNA in the pituitary gland of a white rhinoceros.
- Following successful cloning of the amplified cDNA, they sequenced the nucleotide (nt) and deduced the amino acid sequences. This allowed them to understand the genetic makeup of the LHbeta subunit gene.
- A Southern blot analysis was used on Indian rhinoceros genomic DNA. This process enabled them to determine the number of copies of the gene present in the genome.
- Primer extension mapping was utilized to find the transcriptional start site of the gene, and a Northern analysis was employed to confirm these findings.
Findings
- The first in-frame stop codon occurred at codon position +122, indicating the absence of a characteristic carboxyl terminal peptide (CTP) extension in the rhinoceros LHbeta subunit.
- The Southern blot analysis aided in confirming that there was a single-copy gene at the rhinoceros LH beta gene locus, similar to horses and donkeys.
- The transcriptional start site of the gene showed an 8 nucleotide 5′-untranslated region (UTR), consistent with most mammalian LHbeta transcripts.
Implications of the Research
- The researchers suggest that rhinoceros diverged from equids before the mutations causing CTP expression and changes to the UTR/proximal promoter region occurred.
- Despite these findings, the research does not exclude the potential expression of a placental chorionic gonadotropin (CG) beta subunit lacking a CTP in rhinoceros.
Cite This Article
APA
Sherman GB, Lund LA, Bunick D, Winn RJ.
(1997).
Characterization and phylogenetic significance of rhinoceros luteinizing hormone beta (LHbeta) subunit messenger RNA structure, complementary DNA sequence and gene copy number.
Gene, 195(2), 131-139.
https://doi.org/10.1016/s0378-1119(97)00080-2 Publication
Researcher Affiliations
- Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois, Urbana 61801, USA. gsherman@uiuc.edu
MeSH Terms
- Amino Acid Sequence
- Animals
- Base Sequence
- Chromosome Mapping
- Cloning, Molecular
- Codon, Initiator
- Codon, Terminator
- Female
- Genome
- Humans
- Luteinizing Hormone / genetics
- Molecular Sequence Data
- Nucleic Acid Hybridization
- Perissodactyla / genetics
- Phylogeny
- Polymerase Chain Reaction
- Promoter Regions, Genetic
- Sequence Analysis, DNA
- Sequence Homology, Nucleic Acid
- Transcription, Genetic
Citations
This article has been cited 1 times.- Meuffels-Barkas J, Wilsher S, Allen WRT, Ververs C, Lueders I. Comparative reproduction of the female horse, elephant and rhinoceros: implications for advancing Assisted Reproductive Technologies (ART).. Reprod Fertil 2023 Jul 1;4(3).
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
