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...

objective: this study was conducted to evaluate the effects of different proportions of marshmallow extract (althaea officinalis l.) on growth performance and carcass composition of common carp (cyprinus carpio). methods: common carp with an average weight of 37.65 ± 4.40 g were fed for two months with a diet supplemented with marshmallow (a. officinalis) extract 0.25%, 0.50 and 1%, and with no...

Two lines of Zea mays were developed as a short-generation model for maize. The Fast-Flowering Mini-Maize (FFMM) lines A and B are robust inbred lines with a significantly shorter generation time, much smaller stature, and better greenhouse adaptation than traditional maize varieties. Five generations a year are typical. FFMM is the result of a modified double-cross hybrid between four fast-flo...

Hormonal control of oocyte maturation in crustaceans is reviewed. The bihormonal control of egg maturation is accomplished by the inhibitory neuropeptides originating in the X-organ/sinus gland neurosecretory system and a host of stimulatory hormonal factors secreted from various sources. Among the gonad stimulatory hormones, steroids play a pivotal role in the control of molting and reproducti...

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 ...

Tight junctions in the mucosal epithelium have essential roles as a mucosal barrier to prevent invasion of microbes into the hen oviduct tissue. The aim of this study was to determine the effects of the egg-laying phase and estradiol on the expression of tight junction molecule "claudins" in the lower oviductal segments in hens. White Leghorn laying and molting hens were used. Molting hens were...

The molting cycle of insects has long been used as a model system for studying development. Studies on hormonal control mechanisms (Wyatt, 1972; Doane, 1973; Willis, 1974), pattern formation (Locke, 1967; Lawrence, 1973) and neuronal development (Edwards, 1969) have effectively used the molting and metamorphic cycles of insects to add to our understanding of development. Two insect species whic...