Oocyte competence and gene expression in parthenogenetic produced embryos from repeat breeder and normally fertile buffaloes (Bubalus bubalis) raised in sub-humid tropical climate

• Published in: Animal reproduction science Vol. 262; p. 107426
• Main Authors: Kumar, Satish, Chaves, Maiana Silva, Ferreira, Anna Clara Accioly, Bezerra da Silva, Ana Flavia, Pereira, Leda Maria Costa, Vale, William Gomes, Filho, Sebastião Tavares Rolim, Watanabe, Yeda Fumie, Melo, Luciana Magalhães, Figueirêdo Freitas, Vicente José de
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2024
• Subjects: Animals; Blastocyst - physiology; Buffaloes - genetics; Chemical activation; Embryo; Embryonic Development - physiology; Female; Fertilization in Vitro - veterinary; Gene Expression; In Vitro Oocyte Maturation Techniques - veterinary; Oocytes - physiology; Repeat breeding; Subfertility; Tropical Climate; Embryo; Subfertility; Chemical activation; Repeat breeding
• ISSN: 0378-4320; 1873-2232
• DOI: 10.1016/j.anireprosci.2024.107426

The reproductive management of the buffalo species still faces several unresolved problems, which directly affect the productivity of the herd, one of them being the presence of repeat breeder females. Given this scenario, this study aimed to verify the developmental competence of oocytes obtained from repeat breeder females and submitted to parthenogenetic activation. In addition, embryo gene expression was compared to normally fertile females. Murrah buffaloes were divided into two groups: repeat breeder (RB, n = 8) and normally fertile or control (CR, n = 7). Cumulus-oocyte complexes (COCs) were aspirated by transvaginal ovum pick-up from estrus synchronized females. The COCs were submitted to IVM for 24 h, and subsequently, the oocytes were activated using ionomycin, followed by 6-DMAP. Afterwards, the presumptive parthenotes were cultured for six or seven days in a microenvironment of 5 % CO2, 5 % O2, and 90 % N2 at 38.5 °C. The expression of OCT4, GLUT1, BCL2 and TFAM genes from blastocysts was evaluated. The overall COCs recovery rate was 70.9 % (190/268). The maturation (57.8 vs 71.1), cleavage (45.2 vs 62.2) and blastocyst (30.1 vs 45.9) rates did not differ (P > 0.05) between RB and CR females, respectively. Similarly, no significant difference (P > 0.05) was observed for the expression of studied genes in both RB and CR females. In conclusion, oocytes obtained from RB were as developmentally competent as those collected from CR females, with similar energy metabolism and in vitro development capacity. Thus, the low fertility rate of repeat breeder buffaloes, when compared to normal cyclic females, must be due to subsequent events to the blastocyst stage. •The overall ultrasound-guided transvaginal ovum pickup rate was more than 70 %.•Both oocyte competence and embryo development were similar for both groups.•The gene expression in parthenogenetic produced embryos was similar in both groups.•The repeat breeding in the buffaloes seems linked to post-blastocyst events.