Category: Uncategorized

NO SINGLE WAY. “To summarize, in simple terms the ways in which sex is determined are plastic and diverse.” https://lnkd.in/dn4azG7 View in LinkedIn

SO ENDS this second weekend on a fungal perspective of why sexual reproduction arose during evolution. Few kingdoms are as sexually diverse and plastic as fungi, and they serve as an extreme reference point for the relatively less plastic reproduction of animals and plants. Regardless, living creatures have devised an enormous varieties of methods to create viable progeny and perpetuate that all-important germline into the future, while limiting inbreeding and creating useful genes for adaptation while purging deleterious genes. No small task. View in LinkedIn

QUANTITATIVE TRIGGER. “Finally in some lines of the zebra fish Danio rerio sex appears to be a quantitative trait, in which genes on multiple different chromosomes come together in allelic combinations that favor either female or male fate. This quantitative sex determining system has been termed polygenic sex determination (PSD).” https://lnkd.in/dn4azG7 View in LinkedIn

THE SECOND DIVIDING LINE. “Taken from the perspective of diverse and plastic sex chromosomes and mating-type loci from at least 5 of the 8 supergroups of the eukaryotes, there seems to be nothing ancestral or static about sex determination.” https://lnkd.in/dn4azG7 View in LinkedIn

TEMPERATURE + STRUCTURE TRIGGERS. “Yet other species appear to be hybrids of the two with features of both environmental and chromosomal sex determination.” https://lnkd.in/dn4azG7 View in LinkedIn

ONE DIVIDING LINE. “Phylogenetic reconstructions across the fungal kingdom support the conclusion that bipolar mating type is an ancestral state and the tetrapolar configuration is a derived state.” https://lnkd.in/dn4azG7 View in LinkedIn

TEMPERATURE TRIGGER. “In some animals, including turtles and crocodiles, the temperature at which an egg hatches determines sexual identity and this is called Environmental Sex Determination (ESD) to distinguish it from Chromosomal Sex Determination (CSD).” https://lnkd.in/dn4azG7 View in LinkedIn

FUNGAL MATING TRANSITIONS. “The transition from tetrapolar to bipolar has occurred several times independently in the Basidiomycota, and other examples include Ustilago hordei and Malassezia species.” https://lnkd.in/dn4azG7 View in LinkedIn

ADVANTAGEOUS SYSTEM. “It is thought to be these differences in the frequency of outcrossing and inbreeding that provided the evolutionary pressure for transitions between bipolar and tetrapolar mating systems.” https://lnkd.in/dn4azG7 View in LinkedIn

FUNGAL ADVANTAGE. “Because any given progeny is only interfertile with 25 % of its siblings (A1B2 can mate with A2B1 but not with A1B1 or A2B2), the tetrapolar configuration not only promotes outcrossing but also leads to inbreeding depression.” https://lnkd.in/dn4azG7 View in LinkedIn