Elevated CO2 affects shell dissolution rate but not calcification rate in a marine snail

As CO₂ levels increase in the atmosphere, so too do they in the sea. Although direct effects of moderately elevated CO₂ in sea water may be of little consequence, indirect effects may be profound. For example, lowered pH and calcium carbonate saturation states may influence both deposition and dissolution rates of mineralized skeletons in many marine organisms. The relative impact of elevated CO₂ on deposition and dissolution rates are not known for many large-bodied organisms. We therefore tested the effects of increased CO₂ levels—those forecast to occur in roughly 100 and 200 years—on both shell deposition rate and shell dissolution rate in a rocky intertidal snail, Nucella lamellosa. Shell weight gain per day in live snails decreased linearly with increasing CO₂ levels. However, this trend was paralleled by shell weight loss per day in empty shells, suggesting that these declines in shell weight gain observed in live snails were due to increased dissolution of existing shell material, rather than reduced production of new shell material. Ocean acidification may therefore have a greater effect on shell dissolution than on shell deposition, at least in temperate marine molluscs.     

A re-examination of the cloacal sacs and gland of the blind snake,Leptotyphlops dulcis (Reptilia: Leptotyphlopidae)

The cloacal sacs of Leptotyphlops dulcis are nonglandular, posterior evaginations of the cloaca. The median cloacal gland is tubuloalveolar. Similar unpaired cloacal glands as well as paired sacs are noted in certain colubrid snakes. Terminology applied to these cloacal derivatives is discussed, and a standardization of names is provided.     

Osteolysis in Trichinella spiralis infected vs noninfected rats

1. Based upon the present inability to describe the mechanism by which calcification takes place, and the unexplored metabolism of calcium during trichinosis, studies of rat bone involvement were undertaken. 2. Significant (P less than 0.05) differences were found in experimental (Trichinella spiralis infected) rat femurs vs those of noninfected rats. 3. Analysis by atomic absorption spectroscopy, dry femur weight, and tensile stress resistance indicated an overall reduction in calcium content. 4. This calcium reduction is due to active cyst calcification. 5. Results confirming this finding revealed significant (P less than 0.05) differences at days 60-80 postinfection (the beginning of cyst calcification.     

Aging and reproductive performance in langur monkeys (Presbytis entellus)

Analysis of data on age and reproductive performance in 16 captive female Hanuman langurs (Presbytis entellus) shows that adult females under the age of 6 years and over the age of 19 years had the lowest rates of reproductive success as measured by the production of viable young that survived beyond 30 days of age. With the possible exception of one female, females over the age of 19 years experienced a variety of idiosyncratic reproductive problems but did not experience a true menopause as defined by total cessation of menstrual cycles. There was no support for the hypothesis that langur monkey females have evolved a lengthy postreproductive period.     

Localisation of the myotonic dystrophy locus to 19q13.2–19q13.3 and its relationship to twelve polymorphic loci on 19q

Summary The order of fourteen polymorphic markers localised to the long arm of human chromosome 19 has been established by multipoint mapping in a set of 40 CEPH (Centre d'Étude de Polymorphisme Humain, Paris) reference families. We report here the linkage relationship of the myotonic dystrophy (DM) locus to twelve of these markers as studied in 45 families with DM. The resulting genetic map is supported by the localisation of the DNA markers in a panel of somatic cell hybrids. Ten of the twelve markers have been shown to be proximal to the DM gene and two, PRKCG and D19S22, distal but at distances of approximately 25 cM and 15 cM, respectively. The closest proximal markers are APOC2 (apolipoprotein C-II) and CKM (creatine kinase, muscle) approximately 3 cM and 2 cM from the DM gene respectively, in the order APOC2-CKM-DM. The distance between APOC2, CKM and DM (of the order of 2 million base pairs) and their known orientation should permit directional chromosome walking and jumping. The data presented here should enable us to determine whether or not new markers are distal to APOC2/CKM and thus potentially flank the DM gene.