Ant colonies are commonly thought to have a stable and simple family structure, with one or a few egg-laying queens and their worker daughters. However, recent genetic studies reveal that the identity of breeding queens can vary over time within colonies. In several species, some queens are apparently specialized to enter established colonies instead of initiating a new colony on their own. The...

This study aimed to decrease the cholesterol content of egg yolk of laying hens through inclusion of barley malt rootlets in the diets. Forty-two, 54-week-old, Lohman laying hens were fed for a 12 weeks laying period on 3 iso-caloric and iso-nitrogenous diets contained 0 (control), 25.5 or 51.1g barley malt rootlets/kg. Inclusion of barley malt rootlets at 25.5 or 51.1g/kg diet significantly de...

Understanding which parties regulate reproduction is fundamental to understanding conflict resolution in animal societies. In social insects, workers can influence male production and sex ratio. Surprisingly, few studies have investigated worker influence over which queen(s) reproduce(s) in multiple queen (MQ) colonies (skew), despite skew determining worker-brood relatedness and so worker fitn...

We have investigated the neurotransmitters used to control egg-laying in C. elegans. Previous studies suggested that 5-HT released by the HSN motor neurons stimulates egg laying, and that tricyclic antidepressants potentiate egg laying by blocking reuptake of 5-HT by the HSN neurons. We report studies of the wild type and a mutant that lacks detectable 5-HT that suggest 5-HT is not required for...

The influence of dietary oxidized oil was studied on laying hen performance, egg quality and blood metabolites.  Experiment was conducted on 160 laying hens (Hy-Line W-36, 54-61 wk of age) in a completely randomized design with five treatments and four replicated cages containing eight birds per cage. Dietary treatments replaced fresh soybean oil in the control diet (3% fresh soybean oil, 15.25...

Haplodiploidy results in relatedness asymmetries between colony members of highly eusocial Hymenoptera. As a consequence, queen and reproductive workers are more related to their own sons than to each other's male offspring. Kin selection theory predicts multiple optima in male parentage: either the queen or the workers should produce all the males. Nevertheless, shared male parentage is common...

C. elegans hermaphrodites are self-fertile, and their rate and temporal pattern of egg-laying are modulated by diverse environmental cues. Egg-laying behavior has served as an important phenotypic assay for the genetic dissection of neuronal signal transduction mechanisms. This chapter reviews our current understanding of the neuronal and neurochemical mechanisms underlying the control of egg-l...

The cell provisioning and oviposition process (POP) is a unique characteristic of stingless bees (Meliponini), in which coordinated interactions between workers and queen regulate the filling of brood cells with larval resources and subsequent egg laying. Environmental conditions seem to regulate reproduction in stingless bees; however, little is known about how the amount of food affects quant...