Assessment of growth hormone gene polymorphism effects on reproductive traits in Holstein dairy cattle in Tunisia
<p>Research to assess the effect of single genes on reproductive traits in bovine species is imperative to elucidate genes' functions and acquire a better perspective of quantitative traits. The present study was undertaken to characterize genetic diversity in the bovine growth hormone (G...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-12-01
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| Series: | Archives Animal Breeding |
| Online Access: | https://www.arch-anim-breed.net/61/481/2018/aab-61-481-2018.pdf |
| Summary: | <p>Research to assess the effect of single genes on reproductive traits in
bovine species is imperative to elucidate genes' functions and acquire a
better perspective of quantitative traits. The present study was undertaken
to characterize genetic diversity in the bovine growth hormone (GH) gene in a
population of 410 Holstein dairy cows in Tunisia. The analyses were based on
single nucleotide polymorphisms, and GH-<i>Alu</i>I and GH-<i>Msp</i>I detections and genotyping
were carried out using the polymerase chain reaction-restriction
fragment length polymorphism (PCR-RFLP) method. Data were analyzed using a mixed linear model with the MIXED procedure
to reveal the possible effect of GH genotypes on reproductive traits.
The frequency data of <i>Alu</i>I(L//V) and <i>Msp</i>I(<span class="inline-formula">+</span>//<span class="inline-formula">−</span>)
alleles were 87.04//12.96 and 70.06//29.94, respectively.
The distribution of the frequency of GH
genotypes for LL/LV/VV and (<span class="inline-formula">−</span>/<span class="inline-formula">−</span>)//(<span class="inline-formula">+</span>/<span class="inline-formula">−</span>)//(<span class="inline-formula">+</span>/<span class="inline-formula">+</span>) were
77.75//18.59//3.66 and 15.37//29.13//55.50, respectively. The results of the
statistical analyses proved that GH-<i>Alu</i>I showed a substantial favorable
effect on exanimate traits except for the age at first calving; however, only
a suggestive effect of GH-<i>Msp</i>I on the calving interval (CI) and the days open (DI) was
found. The homozygous LL genotype seemed to be advantageous with respect to the
CI and the DI compared with LV and VV genotypes. Heterozygous <i>Msp</i>I(<span class="inline-formula">+</span>/<span class="inline-formula">−</span>) cows
tended to have a longer CI and DI than <i>Msp</i>I(<span class="inline-formula">+</span>/<span class="inline-formula">+</span>) and
<i>Msp</i>I(<span class="inline-formula">−</span>/<span class="inline-formula">−</span>) cows, but the difference was not statistically significant.
A significant effect of different GH-<i>Alu</i>I–<i>Msp</i>I combined genotypes was
found on the number of inseminations per conception, the CI and
the DI, and the LL/– combined genotype seemed to be associated with
better reproductive performance.
Based on these results, the LL genotype of the GH locus can be
considered to be a favorable genotype for reproductive traits in Holstein dairy
cattle, although these findings need to be confirmed by further research before
polymorphisms can be used in a marker-assisted selection program.</p> |
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| ISSN: | 0003-9438 2363-9822 |