891B Poster - 14. Neural circuits and behavior
Friday April 08, 2:00 PM - 4:00 PM

Authors:
Cazmir Sarnacki ¹; Justin Lilley ¹; Ryan Blackmer ¹; Jonathan Wassink ¹; Erika Spafford ¹; Jordan Yokubonus ¹; Eric Gonzales ^1,2; Lauren Gerritson ¹; Anna Prince ¹; Martin Burg ^1,2

Affiliations:
1) Dept. of Biomedical Sciences, Grand Valley State University, Allendale, MI; 2) Dept. of Cell & Molecular Biology, Grand Valley State University, Allendale, MI

Keywords:
g. courtship and mating; j. physiology of adult organs

The study of histamine and its function in Drosophila melanogaster has primarily focused on its role as a neurotransmitter used by photoreceptors¹ and its effects on a number of other behaviors, such as grooming, thermal preference, and sleep². Recently, we have identified histamine-like immunoreactivity in a vacuole like compartment (VLC) of secondary cells in the male accessory gland. This immunoreactivity is eliminated by null mutations in the Hdc gene that encodes the enzyme histidine decarboxylase³. Previous studies have shown that secondary cells are responsible for enabling a number of post-mating responses including increased egg laying, enhanced sperm viability, and reduced female receptivity to copulation⁴. For this analysis, Oregon-R female flies were conditioned with either wild-type, Hdc^JK910, or Hdc^P211 males, followed by wild-type males at 1, 4, and 10 days after the conditioning copulation. In the current study, we demonstrate that elimination of histamine via the Hdc^P211 or Hdc^JK910 mutations appears to alter the female receptivity to copulation 1 day after copulation, inceasing receptivity when compaared to wild-type. To determine whether the loss of histamine was affecting this phenotype by disrupting the differentiation of secondary cells (or altering their numbers), we examined wild-type, Hdc^JK910, or Hdc^P211 male accessory glands in which secondary cells were marked by GFP labeling. The wild-type and mutant flies were examined at several different ages for the presence of histamine, dlg protein as well as GFP to determine whether large deviations were observed in the number of secondary cells or in the patterning of the accessory gland. Results for both mutant Hdc alleles indicate that secondary cells are still able to differentiate when histamine is absent in the accessory gland, but the number of cells present appears to be consistently reduced when compared to wild-type flies.
References:
1. Burg et al., 1993, EMBO J. 12(3):911-919.
2. Oh et al., 2013, PLoS ONE 8(7):e68269
3. Burg et al., 2019, 60th Drosophila Research Conf., Poster 676
4. Gligorov et al., 2013, PLoS Genetics 9:e1003395.
AP was supported by a GVSU S3 William Schroeder Undergraduate Endowed Fellowship in Chemistry and JW by a GVSU S3 Fellowship for GVSU.