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VARIANT PARASEXUAL. “We also know about an unusual parasexual cycle that is extant in the most common human fungal pathogen, Candida albicans. In this species, mating occurs between diploids when the mating-type locus is homozygous (a/a and α/α) and the cells switch to a specialized mating cell type called opaque.” https://lnkd.in/ebVhXPf View in LinkedIn

ASPERGILLUS PARASEXUAL CYCLES. “More rapidly growing variants readily arise from homozygous diploids, but not from the corresponding haploid “parent,” and they are then reduced to a haploid state. The faster growing variants prove to harbor multiple recessive alleles, reciprocally epistatic, that together are beneficial but individually are deleterious, and thus they can only accumulate in the diploid and then be released during parasexual genome reduction. These studies illustrate the capacity of haploid-diploid-haploid parasexual cycles to generate genotypic and phenotypic diversity de novo.” http://cshperspectives.cshlp.org/content/6/3/a016154.full View in LinkedIn

THE SHELTERED DIPLOID. “Aspergillus has a bona fide homothallic (selfing) sexual cycle, but also undergoes a parasexual cycle under laboratory conditions: Diploids are generated from haploid progenitors by hyphal fusion and the resulting diploid then loses chromosomes randomly to return to the haploid state. Recent studies have shown that this parasexual cycle provides access to a sheltered diploid state that can serve as a capacitor for evolution.” https://lnkd.in/ebVhXPf View in LinkedIn

TWO PHASES. “As one must walk before one can run, the fusion of cells may have led to early parasexual cycles from which true meiotic sexual cycles evolved at a later time.” https://lnkd.in/ebVhXPf View in LinkedIn

CUMBERSOME. “Increases in genome size/ploidy are expected to eventually become deleterious, however, one challenge being to organize a successful mitosis, another to regulate appropriate levels of gene expression. Hence, there would presumably have been positive selection for the acquisition of mechanisms to maintain copy number at a manageable size.” https://lnkd.in/ebVhXPf View in LinkedIn

INTEGRATION. "Capra et al., revealed that new genes in yeast become more integrated into cellular networks over time." https://lnkd.in/dvpUaYF View in LinkedIn

"PSEUDOGENES are conventionally thought as dead genes which play no functional roles, but may evolve functions in regulating expression of related genes. Zheng et al. recently found that many mammalian pseudogenes are transcribed and thus may still function." https://lnkd.in/dvpUaYF View in LinkedIn

GENE NETWORKS. "Integration appears to be driven by natural selection. Several new genes have become new hubs. Gene expression networks can be rapidly and globally reshaped in evolution by new genes." https://lnkd.in/dvpUaYF View in LinkedIn

NON-CODING SEGMENTS. "Not all new genes code for proteins. Noncoding RNAs were found to play an important role in neuronal functions in the early 1990s. A large number of functional RNAs from noncoding regions have been reported to play vital roles in a wide variety of organisms. MicroRNAs appear to turn over rapidly, but can be strongly influenced by positive selection." https://lnkd.in/dvpUaYF View in LinkedIn

ASSIMILATION OF NEW GENES. "New genes can also be quickly integrated into existing gene networks. Chen et al., observed that almost all young essential genes have been assimilated into protein-protein physical interaction networks in Drosophila and a significant number of these young genes have developed multiple interactions with old genes." https://lnkd.in/dvpUaYF View in LinkedIn