Sarco/endoplasmic reticulum Ca ATPase (SERCA) transcript abundance in Y-organs and ecdysteroid titer in hemolymph during a molting cycle of the Blue Crab, Callinectes sapidus.

Crustacean growth is characterized by molting, whereby the old exoskeleton is shed and replaced by a new and larger version. The cellular events that lead to molting are driven by steroid hormones (ecdysteroids) secreted by paired endocrine glands (Y-organs). Between molts, ecdysteroid production is suppressed by a polypeptide molt-inhibiting hormone (MIH) released from neurosecretory cells in the eyestalks.

Silicification of the medial tooth in the blue crab Callinectes sapidus.

Observations of cuticular structures mineralized with silica within the Crustacea have been limited to the opal teeth of copepods, mandibles of amphipods, and recently the teeth of the gastric mill in the blue crab Callinectes sapidus. Copepod teeth are deposited during premolt, with sequential elaboration of organic materials followed by secretion of silica into the tooth mold. The timing of mineralization is in stark contrast to that of the general integument of crustaceans in which calcification is completely restricted to the postmolt period.

Structure, molting, and mineralization of the dorsal ossicle complex in the gastric mill of the blue crab, Callinectes sapidus.

This study examined the mesocardiac and urocardiac ossicles in the gastric mill of the blue crab to describe its structure, mineralization, and dynamics throughout the molt cycle, and to assess its possible utility in age determination. Morphologically, the mineralized ossicles are similar to the calcified dorsal carapace having a lamellate structure comprised of sheets of chitin/protein fibrils. Staining with acridine orange showed the same arrangement of an epicuticle, exocuticle, and endocuticle.

Molecular cloning of a plasma membrane Ca²⁺ ATPase (PMCA) from Y-organs of the blue crab (Callinectes sapidus), and determination of spatial and temporal patterns of PMCA gene expression.

Existing data indicate that a stage-specific increase in intracellular free Ca(2+) stimulates ecdysteroid production by crustacean molting glands (Y-organs). The concentration of Ca(2+) in cytosol is controlled mainly by proteins intrinsic to the plasma membrane and to the membranes of organelles. Several families of proteins are involved, including Ca(2+) channels, Ca(2+) pumps (ATPases), and Ca(2+) exchangers.

Stage-specific changes in calcium concentration in crustacean (Callinectes sapidus) Y-organs during a natural molting cycle, and their relation to the hemolymphatic ecdysteroid titer.

Secretion of ecdysteroid molting hormones by crustacean Y-organs is suppressed by molt-inhibiting hormone (MIH). The suppressive effect of MIH on ecdysteroidogenesis is mediated by one or more cyclic nucleotide second messengers. In addition, existing data indicate that ecdysteroidogenesis is positively regulated (stimulated) by intracellular Ca(++).

Molecular cloning of a putative crustacean hyperglycemic hormone (CHH) isoform from extra-eyestalk tissue of the blue crab (Callinectes sapidus), and determination of temporal and spatial patterns of CHH gene expression.

Crustacean hyperglycemic hormone (CHH) is a polypeptide neurohormone involved in regulation of multiple physiological processes. We report here the cloning from thoracic ganglia of the blue crab (Callinectes sapidus) a cDNA (CsCHH-2) encoding a putative CHH isoform (CsCHH-2). CsCHH-2 is structurally similar to a putative preproCHH (CsCHH-1) previously cloned from eyestalk ganglia of C.

Studies of a receptor guanylyl cyclase cloned from Y-organs of the blue crab (Callinectes sapidus), and its possible functional link to ecdysteroidogenesis.

Crustacean Y-organs synthesize ecdysteroid molting hormones. Synthesis of ecdysteroids by Y-organs is negatively regulated by a polypeptide neurohormone, molt-inhibiting hormone (MIH). Our laboratory has recently cloned from Y-organs of the blue crab (Callinectes sapidus) a cDNA (CsGC-YO1) encoding a putative receptor guanylyl cyclase (CsGC-YO1).

Carapace repair in the green crab, Carcinus maenas (L.).

Formation of a circular hole 8-10 mm in diameter in the calcified layers of the carapace from crabs in stage C of the molt cycle stimulates the tissue under and adjacent to the injury to deposit a unique calcified cuticular material below the intact membranous layer. Deposition was followed for 69 days using light microscopic histology, histochemistry, and scanning electron microscopy. Quantitative analyses of CaCO were conducted using atomic absorption spectrophotometry and Gran titration.