# Polymorphism of the BMPR1B Variants for Prolific Traits in the Indonesian Local Ettawah Goat

## TL;DR

This study identifies genetic variations in the BMPR1B gene linked to higher fertility in Indonesian Ettawah goats, suggesting potential for breeding improvements.

## Contribution

The study introduces a dual-primer PCR method to detect BMPR1B polymorphisms and links the G allele to increased prolificacy in Ettawah goats.

## Key findings

- The BMPR1B gene's G allele is associated with higher fecundity in Indonesian Local Ettawah Goats.
- Homozygous GG genotype showed significantly higher prolificacy compared to AA and GA genotypes.
- A dual-primer PCR approach effectively identifies BMPR1B polymorphisms for breeding applications.

## Abstract

A polymerase chain reaction (PCR) assay, employing a novel combination of A and G allele primers of the Bovine Morphogenetic Protein Receptor type 1B (BMPR1B) gene, revealed significant polymorphism within the Indonesian Local Ettawah Goat (ILEG). Polymorphism analysis classified the goats into three distinct genotypes: homozygous allele A (AA), heterozygous (AG), and homozygous allele G (GG). These findings also indicated a correlation between the presence of the G allele and increased prolificacy and highlighted the potential of BMPR1B variants as genetic markers for enhanced reproductive performance and overall livestock improvement.

The Indonesian Local Ettawah Goat (ILEG) exhibits substantial genetic variation, suggesting its potential for high productivity and promote sustainable practices in farm animal breeding. This study aimed to investigate the molecular characteristics of prolific ILEG by identifying potential candidate genes through polymerase chain reaction (PCR) analysis of the bone morphogenetic protein receptor type 1B (BMPR1B) gene with two variants: alleles G and A. The research involved PCR amplification and sequencing of the BMPR1B A allele, followed by a combined PCR approach integrating both A and G alleles for genotyping. Blood samples were collected from 73 does with documented prolificacy history and 358 does without prolificacy histories, sourced from seven village breeding operations in East Java. PCR amplification yielded fragments of 556–1181 base pairs in all samples. Haplotype analysis revealed 15 unique haplotypes with a diversity of 0.94 and a mutation frequency of 27.15%. Integration of the BMPR1B alleles G and A revealed polymorphic prolific traits. Polymorphism analysis of 385 ILEGs demonstrated allele frequencies of 0.55 for allele A and 0.45 for the allele G. Average fecundity rates associated with the BMPR1B polymorphism were 1.49 offspring for the homozygous AA, 1.60 for the heterozygous GA, and 1.89 for the homozygous GG. While overall differences among genetic groups were approached statistically significantly (Kruskal–Wallis, p = 0.056), pairwise comparison (Mann–Whitney test) revealed that homozygous GG was significantly associated with higher prolificacy compare to the heterozygous GA (p = 0.029) and homozygous AA (p = 0.040). Similar results were also obtained from data without documented history. These findings suggest that the GG polymorphism of BMPR1B may increase prolificacy in ILEG. Furthermore, the higher frequency of allele G highlights the importance of considering prolificacy traits in breeding selection strategies to enhance sustainable genetic improvement and increase litter size in ILEG. It is recommended to apply dual-primer specific amplification and fragment size differentiation as key molecular approaches for polymorphism of the BMPR1B gene and prolificacy, since these methods can highlight genetic variation and provide valuable markers for breeding programs of the Indonesian Local Etawah Goat.