Insect molting and metamorphosis are regulated by two major insect hormones, the juvenile hormone (JH) and ecdysteroids. Ecdysteroids initiate the molting process, whereas JH dictates the character of a molt. At the critical period of ecdysteroid rise, the presence or absence of JH directs larval-larval molting or metamorphosis. Ecdysteroid after binding with its receptor activates the expressi...

A study was conducted to evaluate skeletal quality and eggshell parameters of molted hens at the end of the second laying cycle. Sixty Single Comb White Leghorn hens were used for this study. There were 2 controls and 4 molting treatments: full-fed control 1 (82 wk old; FF1), full-fed control 2 (122 wk old; FF2), feed withdrawal (FW), 100% alfalfa (A100), 90% alfalfa/10% layer ration (A90), and...

In crustaceans, like all arthropods, growth is accompanied by a molting cycle. This cycle comprises major physiological events in which mineralized chitinous structures are built and degraded. These events are in turn governed by genes whose patterns of expression are presumably linked to the molting cycle. To study these genes we performed next generation sequencing and constructed a molt-rela...

Stable isotope ratios of hydrogen (dD) and carbon (d13C) in feathers collected from Painted Buntings (Passerina ciris (L., 1758)) breeding in the midwestern United States revealed a surprising degree of variation in dD, as well as a clear bimodal signal in d13C in the innermost primary feather. Because this population does not molt on the breeding grounds, we reasoned that these observations co...

After molting to maturity, female blue crabs must rebuild muscles atrophied to permit molting and grow larger ones commensurate with the larger exoskeleton. They also must acquire energy for oogenesis and for migration to high-salinity spawning habitat, a distance of >150 km for females mating in the Upper Chesapeake Bay. Using telemetry and mark–recapture techniques, postcopulatory females in ...

Cryptocyanin, a copper-free hexameric protein in crab (Cancer magister) hemolymph, has been characterized and the amino acid sequence has been deduced from its cDNA. It is markedly similar in sequence, size, and structure to hemocyanin, the copper-containing oxygen-transport protein found in many arthropods. Cryptocyanin does not bind oxygen, however, and lacks three of the six highly conserved...

SYNOPSIS. The exoskeleton of crustaceans and insects is formed by cells of the hypodermis, but several hemolymph proteins contribute to the synthesis of the new exoskeleton. These hemolymph proteins share a surprising degree of sequence similarity and are members of the hemocyanin gene family. Copper-containing prophenoloxidases of crustaceans and insects are directly involved in cross-linking ...

The project was carried out to compare the performance of molted layers by aluminium oxide supplementation in cages and on litter floor system. Seventy two Single Comb White Leghorn commercial layers (60 weeks old) were divided into six experimental units of 12 layers each. These experimental units were randomly divided into two groups, each consisting of three experimental units, one group was...