The high sulphur proteins of wool: Towards an understanding of sheep breed diversity

High sulphur proteins (HSPs) form part of the matrix surrounding the intermediate filaments in the cortical cells of the wool fibre. There are three known families of HSPs, comprising in excess of 40 components and their molecular weights range from 10-30 kDa. Here we report the use of the increased resolving power of isoelectric focusing in the first dimension of two-dimensional electrophoresis and modern gel comparison software to investigate the nature of within- and between-breed variations amongst the proteins of three breeds of sheep: Merino, Romney and Corriedale. In agreement with past studies we observed very little variation in the intermediate filament protein content in wool, both between and within these three sheep breeds. Instead, most of the observed variation occurred among the HSPs, along with some minor variation among the high glycine-tyrosine proteins. Breed-specific differences were observed in the HSP patterns in the wool proteome maps. Merino sheep were found to exhibit the simplest HSP expression patterns, with eight major spots linked to form four pairs. In contrast, the Romney and Corriedale HSP patterns exhibited more spots at lower isoelectric point values (around 4.8), while some of the lower molecular weight HSPs were less prevalent in Romney sheep and absent from the Corriedales.     

Prolonged absence of myostatin reduces sarcopenia

Sarcopenia is a progressive age-related loss of skeletal muscle mass and strength. Parabiotic experiments show that circulating factors positively influence the proliferation and regenerative capacity of satellite cells in aged mice. In addition, we believe that negative regulators of muscle mass also serve to balance the signals that influence satellite cell activation and regeneration capacity with ageing. Myostatin, a negative regulator of pre- and postnatal myogenesis, inhibits satellite cell activation and muscle regeneration postnatally. To investigate the role of myostatin during age-related sarcopenia, we examined muscle mass and regeneration in young and old myostatin-null mice. Young myostatin-null muscle fibers were characterized by massive hypertrophy and hyperplasia and an increase in type IIB fibers, resulting in a more glycolytic muscle. With ageing, wild-type muscle became increasingly oxidative and fiber atrophy was prominent. In contrast no fiber type switching was observed and atrophy was minimal in aged myostatin-null muscle. The effect of ageing on satellite cell numbers appeared minimal, however, satellite cell activation declined significantly in both wild-type and myostatin-null muscles. In young mice, lack of myostatin resulted in increased satellite cell number and activation compared to wild-type, suggesting a greater propensity to undergo myogenesis, a difference maintained in the aged mice. In addition, muscle regeneration of myostatin-null muscle following notexin injury was accelerated and fiber hypertrophy and type were recovered with regeneration, unlike in wild-type muscle. In conclusion, a lack of myostatin appears to reduce age-related sarcopenia and loss of muscle regenerative capacity.     

Lifestyle Interventions Limit Gestational Weight Gain in Women with Overweight or Obesity: LIFE‐Moms Prospective Meta‐Analysis

Objective

This study aimed to evaluate the effects of varied lifestyle intervention programs designed to ameliorate excess gestational weight gain (GWG) in pregnant women with overweight or obesity compared with standard care, including effects on pregnancy outcomes.

Methods

Seven clinical centers conducted separate randomized clinical trials to test different lifestyle intervention strategies to modify GWG in diverse populations. Eligibility criteria, specific outcome measures, and assessment procedures were standardized across trials. The results of the separate trials were combined using an individual‐participant data meta‐analysis.

Results

For the 1,150 women randomized, the percent with excess GWG per week was significantly lower in the intervention group compared with the standard care group (61.8% vs. 75.0%; odds ratio [95% CI]: 0.52 [0.40 to 0.67]). Total GWG from enrollment to 36 weeks' gestation was also lower in the intervention group (8.1 ± 5.2 vs. 9.7 ± 5.4 kg; mean difference: ?1.59 kg [95% CI:?2.18 to ?0.99 kg]). The results from the individual trials were similar. The intervention and standard care groups did not differ in preeclampsia, gestational diabetes, cesarean delivery, or birth weight.

Conclusions

Behavioral lifestyle interventions focusing primarily on diet and physical activity among women with overweight and obesity resulted in a significantly lower proportion of women with excess GWG. This modest beneficial effect was consistent across diverse intervention modalities in a large, racially and socioeconomically diverse US population of pregnant women.

     

Regional identity of human neural stem cells determines oncogenic responses to histone H3.3 mutants

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Fatigue fracture of mother-of-pearl and its significance for predatory techniques

Specimens of nacre from the pearl oyster Pinctada margaritifera were loaded in bending to various fractions of the load needed to cause fracture. For a small number of cycles, less than about 1000, no changes in compliance or strength were found if the load was less than about 60% of the load necessary to cause failure. Above this fraction the compliance increased, the strength usually decreased but occasionally increased.
We conclude that, because the loading of a shell by a predator is likely to be far less controlled than loading by a machine, causing a shell to break by fatigue fracture is unlikely to be a tactic employed by a predator, though it may happen fortuitously.     

Social organization of Galagos in Kenyan coastal forests: I. Galago zanzibaricus

The social organization of Galago zanzibaricus was studied for the first time and the study included data from two different sites in the coastal forests of Kenya. A combination of mark-recapture and radio-tracking techniques was used to investigate patterns of inter- and intrasexual home range overlap. Associations in sleeping groups indicated social ties between individuals. Patterns of range use were established by radio-tracking focal individuals. Adult males generally had nonoverlapping ranges, shared with one or two females and their offspring with which the male regularly slept. Young females remained longer in their natal ranges than males and reproduced within their natal ranges. Range size and distance traveled per night were similar between the sexes; both sexes probably defended territories. None of the other galago (bushbaby) species studied to date show the degree of close male-female association found in G. zanzibaricus. This study thus extends the variety of social organization documented in nocturnal prosimians.     

Urinary corticosteroid excretion patterns in the okapi (Okapia johnstoni)

Stress is known to alter a variety of biological processes, including behavior and reproduction. It is therefore important to understand the stress levels of animals in captivity, especially those for whom captive breeding is a priority, such as the okapi. Levels of stress hormones can be measured from samples collected noninvasively, such as urine or feces, which are preferable with nondomestic species for whom drawing blood might in itself be a considerable stressor. To understand the excretion of cortisol in urine in the okapi, four (1.3) animals were subject to three injections: saline, 200 IU of an adrenocorticotropic hormone (ACTH) analogue, and 300 IU of the analogue. Their 24‐hr urinary corticosteroid levels were compared with 4 baseline days. Injection with the ACTH analogue significantly increased the urinary corticosteroid levels compared with saline injections and baseline. Eight (3.5) okapi were then observed for 24 hr per day for 5 days to determine their normal patterns of corticosteroid production. The mean corticosteroid levels varied significantly by individual. A significant circadian pattern in urinary corticosteroid was apparent independent of individual or gender, with cortisol rising during the daylight hours and decreasing again at night. Zoo Biol 27:381–393, 2008. © 2008 Wiley‐Liss, Inc.