Meeting Abstract

P3-95   -   Induction of reproductive fate in the Pea Aphid Frederick, JE; Sho, M; Kwa, YC; Li, RY; Davis, GK*; Bryn Mawr College, Bryn Mawr, PA; Bryn Mawr College, Bryn Mawr, PA; Bryn Mawr College, Bryn Mawr, PA; Bryn Mawr College, Bryn Mawr, PA; Bryn Mawr College, Bryn Mawr, PA gdavis@brynmawr.edu https://gdavis.blogs.brynmawr.edu/

The pea aphid, Acyrthosiphon pisum, exhibits remarkable developmental plasticity in response to seasonal changes in photoperiod. In spring and summer, aphids reproduce asexually and are viviparous, yielding large numbers of genetically identical female offspring. The longer nights accompanying the fall induce these asexual aphids to produce sexual males and females, which mate to lay frost-resistant eggs. These eggs diapause through the cold winter months and hatch into asexually reproducing females in the spring, founding new clonal populations. Among other aspects of the polyphenism, we are interested in the process that specifies sexual versus asexual fate during embryonic development. Although previous evidence has implicated juvenile hormone (JH) as playing a role in specifying asexual fate, we present evidence suggesting that maternal JH is not required to specify asexual fate. This result has implications for the mechanism by which pea aphid strains from the southern United States fail to produce sexual progeny in response to changes in photoperiod, an evolutionary loss of plasticity which we also describe.