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ASPARAGUS SEX GENE CONCLUSION. “The work done to date suggests that single-gene sex determination systems may evolve following fixation of null mutations in unlinked but interacting sex-specification genes, or as we show here for garden asparagus, two or more linked genes may act independently during development of female or male reproductive pathways.” https://lnkd.in/gKA5C8N View in LinkedIn

SEXUAL SYSTEM DIVERSITY. “Given the immense diversity in sexual systems across the angiosperms and numerous independent origins of dioecy, we expect different genetic factors will be regulating male and female function in unrelated dioecious lineages.” https://lnkd.in/gKA5C8N View in LinkedIn

EXAPTATION OF OLD GENES. “Taken together, the body of data presented here strongly supports that the evolution of an active Y chromosome in Asparagus was mediated by gene duplication and neofuntionalization of a female suppressor and subsequent expansion of the non-recombining sex determination region.” https://lnkd.in/gKA5C8N View in LinkedIn

MTF CONVERSION. “Dioecy has evolved recently within Asparagus and sex chromosomes are cytogenetically identical with the Y, harboring a megabase segment that is missing from the X. We show that deletion of this entire region results in a male-to-female conversion, whereas loss of a single suppressor of female development drives male-to-hermaphrodite conversion.” https://lnkd.in/gKA5C8N View in LinkedIn

SMALL RNA DIFFERENCES. “Comparisons of small RNA abundance between male and female vegetative and reproductive tissues in garden asparagus show differential sRNA patterns between sexes, but none of the genes within the non-recombining region of the Y exhibit evidence of post-transcriptional regulation involving sRNAs.” https://lnkd.in/gKA5C8N View in LinkedIn

16,000 scientists sign dire warning to humanity http://www.cnn.com/2017/11/14/health/scientists-warn-humanity/index.html View in LinkedIn

SMALL RNA REPRESSION. “Several recent studies have identified sex chromosome genes with floral function, including a sex-linked small RNA-producing gene that ultimately represses anther development in diecious persimmon.” https://lnkd.in/gKA5C8N View in LinkedIn

ANTHER AND STYLAR REPRESSION. “In XX females, anther development ceases before pollen microsoporogenesis occurs and is marked by a degeneration of the tapetal layer. In males, the stylar tube and receptive stigma fail to fully form, resulting in a functionally male flower.” https://lnkd.in/gKA5C8N View in LinkedIn

DRIVERS OF DIOECY. "Dioecy is thought to have evolved independently many times. These transitions may have been favoured by the advantage of avoiding self-pollination and the associated inbreeding depression, by the advantage of sexual specialization or by a combination of both." https://lnkd.in/guzeMTD View in LinkedIn

TWO GENE SYSTEM. “Male and female organs are both initiated in developing garden asparagus flower buds, and differences in the timing of cessation of male pistil development and degeneration of female anthers are suggestive of a two-gene sex determination system.” https://lnkd.in/gKA5C8N View in LinkedIn