TWO NEW MUTANT CHARACTERS ON THE SPERMATHECAE OF THE FEMALES OF DROSOPHILA MELANOGASTER. CELL-DEGENERATION AND SUPERNUMERARY SPERMATHECAE

A new allele of <i>engrailed</i>, <i>en^NK14</i>, causes supernumerary spermathecae in <i>Drosophila melanogaster</i>

“…As previously mentioned, Wexelsen (1928) reported a mutation of females with an extra spermatheca accompanied by dark brown granules. He mapped one of the genes responsible, dg-a, near the two marker genes cn (cinnabar) and c (curved) on II chromosome; en is located between them.…”

“…There are some previous reports of unusual structures in the vicinity of the spermathecae. Wexelsen (1928) showed that females with the mutation degenerated spermatheca (dg-a) had triple spermathecae accompanied by dark brown pigments or brown granules in the epithelial cells of the capsule. Another anomalous structure, SDP (spermathecal duct presence), was recently found inside the duct of the spermatheca in Drosophila females (Hopkins et al, 2020).…”

“…In D. melanogaster, both spermathecae originate from the A8 segment of the genital imaginal disc dur-ing the pupal stage (Epper and Sánchez, 1983;Chen and Baker, 1997;Sánchez et al, 1997;Keisman et al, 2001;Sánchez and Guerrero, 2001;Estrada et al, 2003;Sun and Spradling, 2012). The number of spermathecae is thought to be determined by a genetically controlled developmental program, but supernumerary spermathecae are often observed in D. melanogaster, for instance in a race carrying three spermathecae (Sturtevant, 1925) and in an isolated mutant whose females had three or four spermathecae (Wexelsen, 1928). Importantly, a mutation, spermatheca (spt), gives rise to supernumerary spermathecae in a temperature-dependent manner (Hadorn and Graber, 1946).…”

Growth rate mediates hidden developmental plasticity of female yellow dung fly reproductive morphology in response to environmental stressors

“…We additionally monitored further life history and fitness traits (Dmitriew, 2011;Roff, 1997), notably pupal and total egg-to-adult survival, plus a common indicator of developmental instability, fluctuating asymmetry (FA) of paired morphological traits (Floate & Coughlin, 2010;Hosken et al, 2000;Palmer, 2000;Palmer & Strobeck, 1986;Parsons, 1992;Polak, 2003;Polak & Tomkins, 2013;Van Valen, 1962;Vøllestad et al, 1999;Whitlock, 1996). This specifically addresses the hypothesis that 4S (over)expression in yellow dung flies may represent a genetic aberration (as suggested for Drosophila melanogaster: Hadorn & Garber, 1944;Mather & Harrison, 1949;Singh et al, 2006;Wexelson, 1928), that is, a stochastic, nonadaptive consequence of systemic developmental instability, rather than an (ancestral) adaptation mediated by life-history trade-offs. We further present comparative data for the closely related and ecologically similar S. suilla (see Bernasconi et al, 2001) to demonstrate that spermathecal overexpression is no necessary consequence of accelerated growth, and that this type of (mostly hidden) developmental plasticity has evolved differently at least in two (but likely more) related taxa (cf.…”

Τρανσκριπτομική και πρωτεομική ανάλυση του σημαντικότερου παράσιτου της ελιάς, του εντόμου Bactrocera oleae, με έμφαση στα συστήματα φυλοδιαχωρισμού και ανθεκτικότητας στα εντομοκτόνα

“…Έχουν αναφερθεί περίπου είκοσι μεταλλαγμένα αλληλόμορφα σε αυτό το γενετικό τόπο (Bridges and Brehme, 1944), αλλά περίπου τα μισά από αυτά είτε έχουν χαθεί ή έχουν απορριφθεί. Δύο μεταλλαγμένοι χαρακτήρες που επηρεάζουν τη σπερματοθήκη έχουν περιγραφεί από τον Wexelsen (1928). Ένα από τα χαρακτηριστικά του μεταλλαγμένου γονιδίου "lozenge" είναι η μη γονιμότητα, ή σχεδόν στειρότητα, στα ομόζυγα θηλυκά.…”