Pandey Anand Kumar, Gunwant P, Soni N, Kumar S, Kumar A, Magotra A, Singh I, Phogat J B, Sharma R K, Bangar Y, Ghuman S P S, Sahu S S
Department of Veterinary Clinical Complex, College of Veterinary Sciences, LUVAS, Hisar, 125004, India.
Department of Veterinary Gynaecology and Obstetrics, College of Veterinary Sciences, LUVAS, Hisar, 125004, India.
Theriogenology. 2019 Apr 1;128:1-7. doi: 10.1016/j.theriogenology.2019.01.018. Epub 2019 Jan 26.
Buffaloes have tendency to show seasonal reproduction and remain in anestrus due to limited ovarian activity during summer. The seasonal reproductive behavior is ascribed the effect of melatonin related to photoperiod. Treating animals with melatonin could be a possible strategy to overcome the problem. The role of MTNR1A gene has not been fully explained in the buffalo. Therefore, we conducted a study on 114 buffalo heifers to detect the polymorphic site in MTNR1A gene and further treated them with melatonin implants to investigate the role of most frequent genotype following melatonin treatment on pregnancy. The present investigation is the first to investigate the association between melatonin treated different MTNR1A genotype buffalo and pregnancy. We confirmed SNP at position 72 in 812 bp fragment exon II of MTNR1A gene. RFLP of PCR products with Hpa I enzyme resulted in three genotypes: TT (812bp), CT (812, 743, 69bp) and CC (743, 69bp). Next, buffaloes of each genotype (TT, CC, CT; n = 28 for each) were treated with melatonin implants to compare the conception rate with their corresponding untreated control (n = 10 for each genotype). Melatonin concentrations were higher (P < 0.05) for the treatment groups of all genotypes compared to their respective untreated control from day 1-28. The pregnancy rate was significantly associated with the MTNR1A genotype. The conception rate was higher (P < 0.05) for TT genotype than for the other genotypes of buffaloes treated with melatonin. Furthermore, buffaloes of TT genotype treated with melatonin started exhibiting estrus activity soon from second week of melatonin treatment (14.1 ± 2.1; range: 10-17 days) and were found to be 7.8 times more likely to become pregnant compared to other genotypes following melatonin treatment. In conclusion, TT genotype of MTNR1A gene is more sensitive to melatonin treatment that favours pregnancy in buffaloes during summer.
水牛有季节性繁殖的倾向，由于夏季卵巢活动受限而处于发情间期。季节性繁殖行为归因于与光周期相关的褪黑素的作用。用褪黑素治疗动物可能是解决该问题的一种策略。MTNR1A基因在水牛中的作用尚未得到充分解释。因此，我们对114头水牛小母牛进行了一项研究，以检测MTNR1A基因中的多态性位点，并进一步用褪黑素植入物对它们进行治疗，以研究褪黑素治疗后最常见基因型对妊娠的作用。本研究首次调查了褪黑素处理的不同MTNR1A基因型水牛与妊娠之间的关联。我们在MTNR1A基因外显子II的812 bp片段中的第72位确认了单核苷酸多态性。用Hpa I酶对PCR产物进行限制性片段长度多态性分析产生了三种基因型：TT（812bp）、CT（812、743、69bp）和CC（743、69bp）。接下来，对每种基因型（TT、CC、CT；每种n = 28）的水牛用褪黑素植入物进行治疗，以比较其受孕率与相应的未治疗对照组（每种基因型n = 10）。从第1天到第28天，所有基因型的治疗组褪黑素浓度均高于各自的未治疗对照组（P < 0.05）。妊娠率与MTNR1A基因型显著相关。用褪黑素治疗的TT基因型水牛的受孕率高于其他基因型（P < 0.05）。此外，用褪黑素治疗的TT基因型水牛从褪黑素治疗的第二周开始很快就表现出发情活动（14.1 ± 2.1；范围：10 - 17天），并且发现与褪黑素治疗后的其他基因型相比，其怀孕的可能性高7.8倍。总之，MTNR1A基因的TT基因型对褪黑素治疗更敏感，这有利于水牛在夏季妊娠。
