B-chromosomes and male-biased sex ratio with paternal inheritance in the fairy shrimp Branchipus schaefferi (Crustacea, Anostraca).
This study reports on male-biased sex ratios in west Mediterranean populations of the freshwater anostracan Branchipus schaefferi (Crustacea, Anostraca, Branchipodidae), in contrast to populations elsewhere. Crossing experiments over several generations indicate a clear paternal inheritance of the trait, possibly with a dosage effect. Various mechanisms which may underlie this phenomenon are discussed, the most plausible being the presence of one or more supernumerary ('B') chromosomes--as evidenced by karyological observations--interfering with sex determination and probably having an accumulation mechanism in male individuals.
Beladjal
L
L
Laboratorium voor Ecologie (WE11V), Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium. lynda.beladjal@rug.ac.be
Vandekerckhove
T T M
TT
Muyssen
B
B
Heyrman
J
J
de Caesemaeker
J
J
Mertens
J
J
D000818:Animals; D002875:Chromosomes; D003433:Crosses, Genetic; D033364:Decapoda / Q000235:genetics*; D005260:Female; D008297:Male; D012727:Sex Characteristics; D012744:Sex Ratio