481 fresh fertilized eggs of three Kurdish local chickens (Black with brown neck, White with shank feathering, and White with non-feathering shank) were collected at pre-molting (355 eggs) and post-molting (126 eggs) stages to evaluate external egg traits. A venine caliper was used to determine the length and breadth of eggs to calculate Shape index. Results indicated that egg weight increased ...

The aims of this study were to obtain information on the mechanism of molting and the prolactin hormone levels affecting egg production. The study utilized AP (crossbred of Alabio ♂ with Peking ♀) and PA (crossbred of Peking ♂ and Alabio ♀ ducks) with a total of 180 birds. The observed variables were the duration of cessation of egg production before and after molting, the prolactin hormone lev...

In insects, extra-molting has been viewed as a compensatory mechanism for nymphal growth that contributes to optimize body weight for successful reproduction. However, little is known on the capacity of extra-molting to evolve in natural populations, which limits our understanding of how selection acts on nymphal growth. We used a multi-generational pedigree, individual monitoring and quantitat...

BACKGROUND Molting is an essential biological process throughout the life history of crustaceans, which is regulated by many neuropeptide hormones expressed in the eyestalk. To better understand the molting mechanism in Portunus trituberculatus, we used digital gene expression (DGE) to analyze single eyestalk samples during the molting cycle by high-throughput sequencing. RESULTS We obtained ...

In crustaceans with compound eyes, the corneal lens of each facet is part of the exoskeleton and thus shed during molting. Here we used an optomotor assay to evaluate the impact of molting on visual acuity (as measured by the minimum resolvable angle, α(min)) in the female blue crab, Callinectes sapidus. We found that visual acuity decreases substantially in the days prior to molting and is gra...

Aquatic pollution has led to the accumulation of various xenobiotics in crustaceans. A number of these environmental chemicals have been found to interfere with molting of crustaceans. Results of initial mechanistic studies with Uca pugilator suggest that the disruption of molting results from the disturbance to the Y-organ-ecdysteroid receptor (EcR) axis by xenobiotics. Such disturbance to the...

Precise staging of Caenorhabditis elegans is essential for developmental studies in different environmental conditions. In favorable conditions, larvae develop continuously through four larval stages separated by molting periods. Distinguishing molting from intermolt larvae has been achieved using transgenes with molting reporters, therefore requiring strain constructions, or careful observatio...

Chitin synthase and chitinase play crucial roles in chitin biosynthesis and degradation during insect molting. Silencing of Dicer-1 results in reduced levels of mature miRNAs and severely blocks molting in the migratory locust. However, the regulatory mechanism of miRNAs in the molting process of locusts has remained elusive. In this study, we found that in chitin metabolism, two crucial enzyme...

The aim of this study was to determine the differences in the mucin expression that forms a mucosal surface barrier in the oviduct between laying and molting hens. The lower segments of oviducts (isthmus, uterus, and vagina) of White Leghorn laying and molting hens were collected. Localization and gene expression of mucosal mucin were analyzed by quantitative reverse-transcription PCR of mucin ...

Molting is a critical developmental process for crustaceans, yet the underlying molecular mechanism is unknown. In this study, we used RNA-Seq to investigate transcriptomic profiles of the hepatopancreas and identified differentially expressed genes at four molting stages of Chinese mitten crab (Eriocheir sinensis). A total of 97,398 transcripts were assembled, with 31,900 transcripts annotated...