The second was that, given that brain tissue and testis tissue are among the most expensive to maintain physiologically, and that bats have a very tight energy budget, bigger balls would result in smaller brains.In this section Changing science Fighting fire with fire Bats and balls ReprintsThe team knew, from work done some time ago, that the first part of their hypothesis is true in primates.
The winning organ (a slice of which is pictured), with a third of those 3,500 genes, is the testis.
Dr Pitnick's project, published in this week's Proceedings of the Royal Society, looked at brain size and testis size in 334 of those species.
The first was that in any given species, the average male's testis size as a fraction of body weight will depend on the behaviour of that species' females in particular, how promiscuous those females are.
This is a long tube that leads out of the testis, in which newly formed sperm acquire some of their survival skills, such as their ability to swim.
In bony fishes a sperm duct leads from each testis to a urogenital opening behind the vent or anus.
Germline gene therapy aims to place corrected cells inside the germ line (e.g., cells of the ovary or testis).
Spermatogenic cells migrate into the cysts from a permanent germinal layer, which, depending on the species, may lie among cysts at the periphery of the testes or in a ridge along one margin of the testis.
The male duct system begins as the rete testis, a network within the testis of thin-walled ductules, or minute ducts, that collects sperm from the seminiferous tubules.
