An analysis of CYP19, CYP21 and ER genotypes in Polish Holstein-Friesian cows with regard to the selected reproductive traits

Abstract

The aim of this study was to relate polymorphic variants of CYP19, CYP21 and ER1 genes to reproductive traits in 472 Polish Holstein-Friesian cows. High frequencies of one of the homozygous genotypes were found. The ER1/SnaBI AA homozygotes were not identified. In the first and third lactation, an average calving-to-conception interval (CLVC) in cows of ER1/SnaBI GG genotype was significantly shorter (P ≤ 0.05) than in heterozygous cows. In the cows of ER1/ BglI GG genotype, significantly shorter CLVC (P ≤ 0.05) was observed compared to heterozygotes in the first lactation, whereas in the third lactation, CLVC in homozygous cows was significantly longer (P ≤ 0.05) than in heterozygous ones. It was also found that homozygous cows were characterized by significantly longer calving interval (CLVI; P ≤ 0.05) compared to heterozygotes in the third lactation. Longer CLVCs in CYP19 AA cows were found, compared to heterozygotes, and this difference was significant in the first and third lactation (P ≤ 0.05). Similarly, the average CLVIs were longer in CYP19 AA homozygotes than in heterozygous cows; however, significance was proven only in the third lactation (P ≤ 0.05). Description of the molecular mechanisms regulating reproduction, and thus identification of the individuals of genotypes with optimal potential may facilitate the employment of selected reproductive model by a breeder. Gene polymorphism, calving interval, calving-to-conception interval, pregnancy length, inseminationsAbbreviations: CYP19 -cytochrome P450 aromatase gene, CYP21 -steroid 21-hydroxylase gene, ER -oestrogen receptor gene, CLVC -calving-to-conception interval, CLVI -calving interval, INSEM -number of services per successful conception, PREG -pregnancy length.Genetic improvement of the reproductive traits in dairy cattle is crucial not only for ensuring quantitative aspect of production but mainly for the efficient course of lactogenesis and lactopoesis. It is an extremely difficult process, regulated at many stages in a multifactorial manner. Moreover, coefficients characterizing reproductive traits are of low heritability and there is a small number of described genetic markers associated with reproduction that could be used as potential factors supporting the classical selection methods. Therefore, searching for such markers is admittedly important both for the application and research purposes. So, the analysis of the influence of different polymorphic variants of enzymes crucial for oestrogen synthesis on the reproductive traits or of protein factors mediating their actions seems fully justified.The reproductive cycle of all mammalian females is regulated mainly by oestrogen hormones. They are synthesized through the aromatization of androgens, which, in females, are mainly of ovarian origin. In this complex process, a key role is played by the p450 aromatase, which is an enzymatic complex comprising two proteinsnonspecific microsomal flavoprotein reductase and specific haemoglycoprotein, that is, cytochrome P450 aromatase, coded f...

Molecular Characterization of Cytochrome P450 Aromatase (Cyp19) Gene in Egyptian River Buffaloes

“…1-C). In the opposite to these results in which A allele was not detected, the A allele frequency in the Polish Holstein-Friesian cows was ranged from 92.27 to 93.2% (Szatkowska et al, 2011;Wierzbicki et al, 2014).…”

“…472 Polish Holstein-Friesian cows were screened and found that the calving-toconception interval in the first and third lactation in addition to the calving interval in the third lactation were shorter in AG genotype than AA genotype (Szatkowska et al, 2011).…”

THE ASSOCIATION BETWEEN ERα/ BglI GENOTYPES AND MILK PERFORMANCE IN HOLSTEIN-FRIESIAN AND JERSEY CATTLE. PRELIMINARY STUDY

“…In the studies mentioned, it has been proven that the GG homozygotes' lactation lasts longer than the AG heterozygoes' and that the homozygotes need less time to regenerate after a calf's separation, before their next pregnancy and also that their pregnancy lasts slightly longer. (Szatkowska et al 2010). Another study emphasizes importance of the ERs function in the process of developing a mammary gland.…”

Esmer ve siyah alaca ırkı sığırlarda bazı ekonomik özellikler ile ilişkili gen bölgelerinin PCR-RFLP tekniği ile incelenmesi

“…Sığırlarda yapılan çalışmaların ise sınırlı olduğu ve mevcut çalışmaların genellikle tek bir araştırma grubu tarafından gerçekleştirildiği (Szreder & Zwierzchowski 2004a,b; gözlenmektedir. Bildirilen mutasyonların çeşitli verim özellikleri üzerine etkilerinin incelendiği araştırma sayısı da oldukça sınırlıdır (Szatkowska et al 2011;Zahmatkesh et al 2012). Sığır ERα geninin kodlama yapan ve yapmayan çeşitli bölgelerini kapsayan 2853 bç'lik bir bölgesi ilk kez Szreder & Zwierzchowski (2004a) tarafından ortaya konulmuştur.…”