Oocyte Selection for In Vitro Embryo Production in Bovine Species: Noninvasive Approaches for New Challenges of Oocyte Competence

Abstract

The efficiency of producing embryos using in vitro technologies in livestock species rarely exceeds the 30–40% threshold, indicating that the proportion of oocytes that fail to develop after in vitro fertilization and culture is considerably large. Considering that the intrinsic quality of the oocyte is one of the main factors affecting blastocyst yield, the precise identification of noninvasive cellular or molecular markers that predict oocyte competence is of major interest to research and practical applications. The aim of this review was to explore the current literature on different noninvasive markers associated with oocyte quality in the bovine model. Apart from some controversial findings, the presence of cycle-related structures in ovaries, a follicle size between 6 and 10 mm, large number of surrounding cumulus cells, slightly expanded investment without dark areas, large oocyte diameter (>120 microns), dark cytoplasm, and the presence of a round and smooth first polar body have been associated with better competence. In addition, the combination of oocyte and zygote selection via brilliant cresyl blue (BCB) test, spindle imaging, and the anti-Stokes Raman scattering microscopy together with studies decoding molecular cues in oocyte maturation have the potential to further optimize the identification of oocytes with better developmental competence for in-vitro-derived technologies in livestock species.

cAMP Modulators before In Vitro Maturation Decrease DNA Damage and Boost Developmental Potential of Sheep Oocytes

“…Besides, previous studies in other species showed that forskolin and IBMXs’ beneficial effects on embryo development are also related to an increased ATP, and oxygen consumption [ 22 , 46 ], modulation of lipid content [ 19 ], and reduced spindle abnormalities [ 22 ], amongst others. Along with DNA integrity, these parameters have often been regarded as good indicators of oocyte quality [ 47 , 48 , 49 ].…”

The Resurrection of Mabrokan: Production of Multiple Cloned Offspring from Decade-Old Vitrified Tissue Collected from a Deceased Champion Show Camel

“…The developmental capacity of reconstructed embryos is influenced by the intrinsic quality of oocytes [ 34 ]. Proper nuclear and cytoplasmic maturation is the key element of a good quality oocyte.…”

The Effect of Prolactin on the Quality of Heifer Oocytes Retrieved by Transvaginal Puncture of Follicles

“…Как известно, эффективность IVP технологии определяется не только качеством исходной популяции гамет, выделенных из яичников животных (8,9), но и условиями среды, окружающей ооциты in vitro (10,11). Наиболее важный этап культивирования -это созревание ооцитов.…”

“…Результаты. К настоящему времени достигнут существенный прогресс в разработке IVP технологии у крупного рогатого скота с использованием донорских ооцитов, однако полноценность эмбрионов, развившихся in vitro из OPU-ооцитов, по-прежнему остается значительно более низкой, чем развившихся in vivo (5)(6)(7)(8). Идентификация биологически уместных факторов, отвечающих за регуляцию качества ооцитов в период их созревания in vitro, будет способствовать решению этой проблемы (12)(13)16).…”