Cloning and nucleotide sequence of the equine and elk pituitary pre-prolactin cDNA.

The researchers have successfully cloned and sequenced the pituitary pre-prolactin cDNA in horses and elks. The deduced amino acid sequence of the equine and elk pre-prolactin suggests some conservation across different mammalian species, and the identified polymorphisms in the elk could be useful for genetic identification purposes.

Research Objectives and Methodology

• The goal of this research was to clone and determine the nucleotide sequence of the pre-prolactin (PRL), a protein that plays an essential role in mammalian reproductive physiology, cDNA in horses and elks.
• To achieve this, the researchers used RNA ligation mediated-rapid amplification of cDNA ends (RLM-RACE) and polymerase chain reaction (PCR), widely used techniques in molecular biology, to obtain the pre-PRL cDNA.

Key Findings

• Upon sequencing, two polymorphisms were found in the elk pre-PRL cDNA at positions 96 and 672. However, these were silent mutations, meaning they did not lead to a change in the encoded amino acids (proline and isoline respectively). No such polymorphisms were identified in the horse pre-PRL cDNA.
• The nucleotide sequence for the equine pre-PRL was found to be almost identical (99%) to a previously reported protein sequence, suggesting a high level of gene conservation.
• They also found that the Pre-PRL mRNA is less than 1 kb in length and is highly expressed in the anterior pituitary gland, according to Northern hybridization analysis.
• The elk and equine pre-PRL amino acid sequences were found to be reasonably conserved across different mammalian species, suggesting these species share a relatively recent common ancestor or that this gene has important biological functions that restrict its evolution.

Implications of the study

• This research sheds light on the molecular biology and genetics of mammalian reproductive physiology by revealing the sequence of the pre-PRL cDNA in horses and elks. This information can add to the existing body of knowledge on the biology of these species and could contribute to future genetic research and breeding practices.
• The polymorphisms found in the elk pre-PRL cDNA sequence could be exploited in parentage testing and gene mapping, helping in species conservation strategies, or to identify parentage in managed herds, thereby providing a new tool for wildlife managers and breeders.