Polymorphic microsatellites for the study of newly established populations of the gastropod Cyclope neritea

Both human‐mediated introductions and climatic changes may promote the settlement of species in new areas outside of their natural geographical range. To investigate the settlement of recently established populations of the neogastropod Cyclope neritea, we developed eight microsatellite markers. Their usefulness was studied in two native populations previously found to be monomorphic with mitochondrial markers. The eight loci were found to be polymorphic in both populations, with two to 18 alleles per locus. This result shows promise for these loci in studies of recently founded populations of C. neritea.     

Restriction fragment length polymorphism identification of goat αs1-casein alleles: a potential tool in selection of individuals carrying alleles associated with a high level protein synthesis

The extensive polymorphism of caprine alpha s1-casein, which is controlled by at least seven autosomal alleles segregating in a Mendelian fashion, was investigated by RFLP analysis. Genomic DNA from 77 lactating goats, whose genotypes had been previously determined by electrophoretic analysis of milk proteins, was digested with 11 restriction endonucleases and Southern blots were probed with a radiolabelled ovine alpha s1-casein cDNA. Three enzymes, PstI, TaqI and Rsa I, allowed the unambiguous identification of known alleles alpha s1-CnA, E and O and of the allelic pairs [alpha s1-CnD and F] and [alpha s1-CnB and C]. Evidence for a second null allele, termed alpha s1-CnO', and for an additional allele, designated alpha s1-CnF', was provided, which leads to the identification of nine alleles at the alpha s1-Cn locus, in this species. Although only 15 out of the 45 expected genotypes could be fully ascertained, this procedure allows the identification at birth of animals carrying the alpha s1-CnA, B or C alleles associated with a high alpha s1- and whole-casein content.     

Alvinellids and Sulfides at Hydrothermal Vents of the Eastern Pacific: A Review

SYNOPSIS. At Eastern Pacific hydrothermal vents, alvinellidpolychaetes are among the first metazoans to colonize newlyformed surfaces of sulfide chimneys. In this environment ofrapid mineral precipitation, alvinellids are confronted by steepphysico-chemical gradients and high temporalvariability. Thispaper examines the interaction of alvinellids with chimney mineralizationprocesses and then reviews what is known of mechanisms thatcould enable these worms to deal with potentially toxic levelsof sulfide in their environment. Studies of sulfide chimneysconsistently show mineralogy to be locally modified around alvinellidtubes. This may be linked to sulfide oxidation products thataccumulate in tube material or to the circulation of seawaterthrough the tube. At high worm densities, these local effectsmay have a significant influence on larger scale sulfide accretionprocesses that determine chimney morphology. Alvinellid polychaetesmay have several lines of defense against sulfide. Tubes andmucous layers could act as passive barriers to reduce inwarddiffusion of sulfide across posterior surfaces. Colonizationof epidermal and tube surfaces by bacteria that might be sulfideoxidizing, could create an active external barrier in some species.Sulfide oxidation by tissue homogenates has been demonstratedin two Paralvinella species, where it may serve to protect oxidativerespiration from sulfide entering worm tissues. Sulfide bindingin blood has not been studied in any of the alvinellids.