Energy requirements in mammalian oogenesis

Abstract

In the search for effective methods of biological control of stored products insect-pests, the essential oil of Origanum vulgaris was extracted using Clevenger apparatus and tested on reproduction and mortality of flour moth Ephestia kuehniella. Bio-insecticide works with a double action mechanism; administered by inhalation in pupae, essential oil affects their pupal development. It also disrupts the reproduction of exuviated adults by extending the preoviposition period and reducing the period of egg laying and fecundity because fecundated females cannot live more than four days compared to control group. Moreover, the essential oil administered by inhalation in adults causes a significant mortality rate compared to control group by reducing their lifespan. A repellent effect against larvae and adults of this pest was noticed in this work. This allowed us ranking this oil as "moderately repulsive".

Germ cell dynamics during nest breakdown and formation of the primordial follicle pool in the domestic turkey (Meleagris gallopavo)

“…Conversely, our results show that during the same cellular depletion period in the turkey (e.g., 5–11 dph), the average diameter of germ cells increased 40 to 150% depending on whether the germ cells had been incorporated into primordial follicles or not. As oogenesis in mammals is known to require a significant amount of energy ( Arhin et al., 2018 ), it seems likely that the extra growth in the turkey germ cell would require even more energy and cellular components, either in the form of higher levels of trophic factors and/or an increase in the number of germ cells acting like nurse cells to supply mitochondria and cellular components to the central primary oocyte. Either of these scenarios could result in greater competition for avian germ cells and explain why turkeys exhibit a larger depletion of germ cells during nest breakdown.…”

Oxidative Stress in Reproduction: A Mitochondrial Perspective

“…During final meiotic maturation, mitochondria in oocytes change their localization, probably as a consequence of the cytoplasmic rearrangements of the cytoskeleton occurring during this phase. In mature MII oocytes, they distribute throughout the cytoplasm, with a layer of polarized mitochondria in the subcortical region (reviewed in [ 56 ]). ATP levels increase during polar body extrusion, and higher amounts of ATP have been correlated to higher fertilization rates of mature MII oocytes [ 47 , 48 ].…”

“…ROS levels increase in the final stages of follicle development, and during ovulation, they increase in the granulosa cells of the thin wall of the follicle, inducing apoptosis and leading to a breakage of the wall and the liberation of the cumulus–oocyte complex (COCs) [ 55 ]. Additionally, ROS present in the follicular fluid can influence folliculogenesis and steroidogenesis, and is involved in the initiation of apoptosis in antral follicles (recently reviewed by [ 56 ]). ROS seems therefore to be important for the regulation of follicular growth, but whether they have an active role or appear as a consequence of the higher metabolic activity during final follicle maturation is not proven yet.…”

Maternal transmission of mitochondrial diseases

“…This includes ã 1,000-fold increase in mitochondria (Jansen and De Boer, 1998;Cree et al, 2008;Wai et al, 2008;St John, 2019), which accounts for the largest mitochondrial content amongst all cells in mammals. In spite of this, mitochondria display several characteristics that suggest they are immature and low functional in oocytes (Arhin et al, 2018). In fact, oocytes lacking the pyruvate dehydrogenase E1 alpha 1 (PDHA1), a key gene required for mitochondrial activity, successfully develop during most part of oogenesis and are ovulated (Johnson et al, 2007).…”

“…In fact, oocytes lacking the pyruvate dehydrogenase E1 alpha 1 (PDHA1), a key gene required for mitochondrial activity, successfully develop during most part of oogenesis and are ovulated (Johnson et al, 2007). Thus, although mitochondria do play an essential role during the final steps of oocyte development, the "embryo silent" hypothesis likely extends to oogenesis too (Arhin et al, 2018). Accordingly, somatic cells surrounding the oocyte (i.e., cumulus cells) provide the oocyte with several energetic molecules, including amino acids, cholesterol, pyruvate, AMP, and ATP (Su et al, , 2009Sugiura et al, 2007).…”