Spermatozoa Turtle Maturity
Introduction Turtles are remarkable creatures, but are not known to form social bonds or be monogamous. Like many animals, female turtles are capable of storing sperm inside of them for extended periods, and it is necessary for some turtle species in order to ensure fertilization. In most turtle species, gamete maturation does not occur at the same time of the year; male gametes typically mature in the fall, and the female ovulation typically occurs in the spring time (1). Sperm storage allows females to be inseminated in the fall, hibernate for winter, and then successfully produce a cloth of eggs in the spring, with no need to go looking for a mate (1). This mechanism also allows females turtles an opportunity to indirectly increase their
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Analysis shows that while still being stored in the male epididymis before ejaculation, sperm have a large cytoplasmic droplet attached to the side of them that contains droplets of lipids inside. These droplet are not observed in sperm found in the storage tubules of females and therefor are thought to serve as an energy source for the spermatozoa as the develop and mature in the epididymis before being released. When examining the morphology of spermatozoa stored within the oviducts of females, it has been found that their mitochondria undergo physical changes over the course of storage. Over the course of approximately a year, the onion-shaped mitochondria of sperm were shown to significantly reduce in size. This reduction in size is thought to be caused by the spermatozoa breaking the extra lipoprotein membranes to use as a source of energy while being stored. It is also thought that as the mitochondria turns to its normal double membrane conformation, the spermatozoa is able to ATP through the OXPHOS pathway, which is believed to be blocked in the multi-membrane conformation. These factors are thought to be what contributes to survival of successful sperm storage in females, and places a selective pressure on males that can produce sperm that can be stored for extended periods of
Analysis shows that while still being stored in the male epididymis before ejaculation, sperm have a large cytoplasmic droplet attached to the side of them that contains droplets of lipids inside. These droplet are not observed in sperm found in the storage tubules of females and therefor are thought to serve as an energy source for the spermatozoa as the develop and mature in the epididymis before being released. When examining the morphology of spermatozoa stored within the oviducts of females, it has been found that their mitochondria undergo physical changes over the course of storage. Over the course of approximately a year, the onion-shaped mitochondria of sperm were shown to significantly reduce in size. This reduction in size is thought to be caused by the spermatozoa breaking the extra lipoprotein membranes to use as a source of energy while being stored. It is also thought that as the mitochondria turns to its normal double membrane conformation, the spermatozoa is able to ATP through the OXPHOS pathway, which is believed to be blocked in the multi-membrane conformation. These factors are thought to be what contributes to survival of successful sperm storage in females, and places a selective pressure on males that can produce sperm that can be stored for extended periods of