Relationship between Amino Acid Metabolism and Bovine In Vitro Follicle Activation and Growth

Abstract

The amino acid metabolism of bovine follicles during in vitro growth (IVG) was evaluated to identify potential indicators of health during culture. The bovine ovarian cortex was sliced, prepared as strips, and cultured for 6 days. Tissue samples were examined histologically before and after 6 days of culture, and the degree of follicle activation was classified as either high or low based on the number of growing secondary follicles present (high: 7~11; low: 0~1). In a separate experiment, secondary follicles (diameter range: 100~200 μm) were manually isolated and cultured, and their growth was monitored for 6 days. Cultured follicles were classified as growth or degenerate based on diameter change during culture (growth: +60.5~74.1 μm; degenerate: −28~15.2 μm). Free amino acids and their metabolites were measured in the spent culture medium from each group. In cultured ovarian cortical strips, the concentration of α-aminoadipic acid was significantly higher in the low activation group than in the high group (p < 0.05), while those of methionine, lysine, and arginine were higher in the high activation group. In cultured isolated secondary follicles, concentrations of methionine, tyrosine, histidine, and hydroxyproline were higher in the degenerate group (p ≤ 0.05). In conclusion, amino acid metabolism has the potential to serve as an indicator of primordial follicle activation and subsequent growth rate during bovine IVG.

Physiological high temperatures alter the amino acid metabolism of bovine early antral follicles

“…After centrifugation (9,600 × g ) at 4°C for 15 min, the supernatant was collected and diluted five-fold with 0.02 M HCl. Free amino acids were analyzed using an automatic amino acid analyzer (L-8900; Hitachi, Tokyo, Japan) as previously described [ 31 ]. The list of molecular species and their abbreviations detected by the amino acid analyzer are described below.…”

Use of monosodium-glutamate as a novel dietary supplement strategy for ovarian stimulation in goats

“…In in vitro studies, it was observed that follicular cultivation with the addition of amino acids such as arginine, lysine, and methionine enabled the activation of primordial ovarian follicles in bovines, as observed by Sakaguchi et al (2023). This effect may be related to the inhibition of the homologous tensin and phosphatase pathways (PTEN), which are the main negative regulators of phosphoinositide 3-kinase (PI3K), thus contributing to the perpetuation of dormancy in primordial follicles.…”

In Vitro Growth of Mammalian Follicles and Oocytes

“…Sakaguchi et al [39] investigated the metabolism of amino acids (which assume diverse roles such as protein synthesis, sources of energy and osmotic pressure, and pH adjustment for cell cultures [40]) during IVG to find non-invasive bio markers to predict the health status of follicles. They found possible molecular species that could be the marker for both cortical strip culture for primordial follicular activation (methionine, lysine, arginine, and α-aminoadipic acid) and IVG for secondary follicles (methionine, tyrosine, histidine, and hydroxyproline).…”

“…In conclusion, this Special Issue covers culture systems from a wide range of follicular developmental stages, including primordial follicles [39], secondary follicles [35,39], early antral follicles [31], small antral follicles [41], in vivo grown antral follicles [35], and whole ovarian cultures [37]. Moreover, it consists of studies of four different species, including water buffaloes [31], cattle [33,35,39], mice [37], and pigs [39].…”

“…In conclusion, this Special Issue covers culture systems from a wide range of follicular developmental stages, including primordial follicles [39], secondary follicles [35,39], early antral follicles [31], small antral follicles [41], in vivo grown antral follicles [35], and whole ovarian cultures [37]. Moreover, it consists of studies of four different species, including water buffaloes [31], cattle [33,35,39], mice [37], and pigs [39]. This variety suggests the need to study oocytes from early developmental stages in varied fields, as well as the importance of the development and refinement of culture systems for each follicle's developmental stage.…”