# Genetic diversity and association analysis of the growth hormone gene in local Indonesian chicken

## TL;DR

This study examines how genetic variations in the growth hormone gene affect laying and carcass traits in Indonesian chickens but finds no significant associations.

## Contribution

The study identifies two novel single-nucleotide polymorphisms in the growth hormone gene of local Indonesian chickens.

## Key findings

- Polymorphism was detected at the GH|MspI locus but not at GH|SacI.
- No significant associations were found between GH gene polymorphisms and laying or carcass traits.
- Two novel SNPs, g.3242delG and g.3396_3401del, were identified in Kampung and Sentul chickens.

## Abstract

The aim of this study was to investigate the effects of theGrowth hormonegene, including its additive and dominant components, on laying performance (age at first laying, body weight at first laying, weight of the first egg, total eggs produced by 24 weeks, and total eggs produced by 48 weeks) and carcass attributes (live weight, carcass weight, breast weight, back weight, thigh weight, and wing weight).

A total of 35 Kampung hens and 19 Sentul roosters were used in this study. Genotyping at the GH|MspI and GH|SacI loci was conducted using the restriction fragment length polymorphism (RFLP) method. Association analyses were conducted using analysis of variance, while additive and dominance effects were assessed through generalized linear models implemented in R version 4.3.1.

RFLP analysis revealed polymorphism at the GH|MspI locus but not at GH|SacI. No significant differences in any trait were observed among the GH|MspI genotypes. Similarly, no significant additive or dominance effects were detected. Moreover, nanopore sequencing identified two novel single-nucleotide polymorphisms, g.3242delG and g.3396_3401del, in both Kampung and Sentul chickens.

No significant association was found between these polymorphisms and laying or carcass traits. Additionally, no significant additive or dominance effects were found, implying that these loci did not significantly influence the definition of these traits in Kampung and Sentul chickens.