A neo-sex chromosome that drives postzygotic sex determination in the hessian fly (Mayetiola destructor).
Two nonoverlapping autosomal inversions defined unusual neo-sex chromosomes in the Hessian fly (Mayetiola destructor). Like other neo-sex chromosomes, these were normally heterozygous, present only in one sex, and suppressed recombination around a sex-determining master switch. Their unusual properties originated from the anomalous Hessian fly sex determination system in which postzygotic chromosome elimination is used to establish the sex-determining karyotypes. This system permitted the evolution of a master switch (Chromosome maintenance, Cm) that acts maternally. All of the offspring of females that carry Cm-associated neo-sex chromosomes attain a female-determining somatic karyotype and develop as females. Thus, the chromosomes act as maternal effect neo-W's, or W-prime (W') chromosomes, where ZW' females mate with ZZ males to engender female-producing (ZW') and male-producing (ZZ) females in equal numbers. Genetic mapping and physical mapping identified the inversions. Their distribution was determined in nine populations. Experimental matings established the association of the inversions with Cm and measured their recombination suppression. The inversions are the functional equivalent of the sciarid X-prime chromosomes. We speculate that W' chromosomes exist in a variety of species that produce unisexual broods.
Benatti
Thiago R
TR
Department of Entomology, Purdue University, West Lafayette, Indiana 47907-2089, USA.
Valicente
Fernando H
FH
Aggarwal
Rajat
R
Zhao
Chaoyang
C
Walling
Jason G
JG
Chen
Ming-Shun
MS
Cambron
Sue E
SE
Schemerhorn
Brandon J
BJ
Stuart
Jeffrey J
JJ
D000818:Animals; D001483:Base Sequence; D007446:Chromosome Inversion; D004175:Diptera / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D005260:Female; D008297:Male; D008969:Molecular Sequence Data; D012730:Sex Chromosomes / Q000235:genetics / Q000378:metabolism*; D019849:Sex Determination Processes