Luteal function and blastocyst development in ewes following treatment with PGF(2)alpha and GnRH

Luteal function and blastocyst development were compared in ewes treated with GnRH (100 mug) on Day 1 (Day 0 = day of estrus) or in ewes previously induced into estrus with PGF(2)alpha. In Experiment 1, the duration of estrous cycles of ewes previously treated with PGF(2)alpha were longer (P<0.06) than those that received PGF(2)alpha plus GnRH, GnRH alone, or remained untreated (control) ewes. Progesterone concentrations were lower (P<0.07) on Day 1 and higher (P<0.01) on Days 16 and 17 of the estrous cycles following PGF(2)alpha treatment relative to those of the natural (control) cycles. In Experiment 2, blastocysts of ewes treated with PGF(2)alpha were less developed (P<0.06) by Day 13 of pregnancy than those of the control ewes. The GnRH treatment did not influence any of these characteristics. Treatment with PGF(2)alpha delayed luteal formation during the subsequent estrous cycle, increased the duration of the estrous cycle and slowed the rate of blastocyst development relative to GnRH-treated and untreated ewes.     

Relation of Intergroup Variation in Allogrooming to Group Social Structure and Ectoparasite Loads in Red Howlers (Alouatta seniculus)

We compare the allogrooming behavior of 5 troops (average size = 8.2) of red howlers (Alouatta seniculus) from the Venezuelan Llanos with that of other A. seniculus and Alouatta spp. of the genus. In 126.9 observation hr, we recorded 118 allogrooming events, with an average bout length of 109 sec. Females groomed more frequently than males did, but as groomees there is no significant differences between sexes. Adult males groomed adult females mostly in a sexual context (before copulation). Allogrooming rates differ significantly among groups. There are also significant differences among members of the same troop both as groomers and groomees, which we explain in the context of the social behavior and history of each troop. There is no significant correlation between weight of the groomee and duration of the grooming bout. However, the examination of grooming rates and ectoparasite load suggests that allogrooming may have hygienic consequences. Differences in allogrooming rates among species of Alouatta are related to differences in group kin structure and patterns of female competition, in particular, coalition formation. We conclude that the social structure and the degree of relatedness among individuals within a group (or among individuals in a population in interpopulation comparisons) is a more important determinant of allogrooming rate than body size or group size. Our results emphasize the importance of considering intergroup and interpopulational variation in behavior.     

Observation of a Paradoxical Temperature Increase During Cognitive Stress in Some Chronic Pain Patients

A total of 224 chronic pain somatoform disorder patients without obvious pathophysiology or psychopathology were found to have colder hands than nonpatients. A paradoxical temperature increase (PTI) in response to a cognitive stressor (mental arithmetic) was noted in a subset of these chronic pain patients. Patients were defined as PTI responders if, during cognitive stress, an increase in digital temperature occurred over a prior eyes closed resting condition. It was found that 49.4% of males and 42.6% of females in a total sample of 224 patients demonstrated PTI. The PTI patients had significantly colder hands than non-PTI patients prior to stress. A concurrent SCL measure of sympathetic activation found no difference between the PTI and non-PTI groups either at baseline or during cognitive stress. It appears from this data that PTI is specific to the peripheral vascular system of these patients and may be a marker of psychophysiological dissociation or trauma blocked from consciousness.     

Characterization and molecular genetic complementation of mutants affecting dimorphism in the fungus ustilago maydis

Ustilago maydis, the causal agent of corn smut disease, displays dimorphic growth in which it alternates between a unicellular, nonpathogenic yeast-like form and a dikaryotic, pathogenic filamentous form. Previously, a constitutively filamentous haploid mutant was obtained. Complementation of this mutant led to the isolation of the gene encoding adenylate cyclase, uac1. Secondary mutagenesis of a uac1 disruption strain allowed the isolation of a large number of suppressor mutants, termed ubc, for Ustilago bypass of cyclase, lacking the filamentous phenotype. Analysis of one of these suppressor mutants previously led to the identification of the ubc1 gene, encoding the regulatory subunit of cAMP-dependent protein kinase. In this report we describe the isolation of cosmids containing three new ubc genes, termed ubc2, ubc3, and ubc4. We also describe the morphology of the ubc2, ubc3, and ubc4 mutants in a uac1- background as well as in a background with a functional uac1 gene. In addition, we describe several mutant strains not complemented with any of the genes currently in hand and that are thus presumed to possess mutations in additional ubc genes. Copyright 1998 Academic Press.     

Body size effects and rates of cytochrome b evolution in tube-nosed seabirds

Variation in rates of molecular evolution now appears to be widespread. The demonstration that body size is correlated with rates of molecular evolution suggests that physiological and ecological factors may be involved in molecular rate variation, but large-scale comparative studies are still lacking. Here, we use complete cytochrome b sequences from 85 species of tube-nosed seabirds (order Procellariiformes) and 5 outgroup species of penguins (order Sphenisciformes) to test for an association between body mass and rates of molecular evolution within the former avian order. Cladistic analysis of the 90 sequences estimates a phylogeny largely consistent with the traditional taxonomy of the Procellariiformes. The Diomedeidae, Procellariidae, and Pelecanoididae are monophyletic, while the Hydrobatidae are basal and paraphyletic. However, the two subfamilies within the Hydrobatidae (Hydrobatinae and Oceanitinae) are monophyletic. A likelihood ratio test detects significant deviation from clocklike evolution in our data. Using a sign test for an association between body mass and branch length in the seabird phylogeny, we find that larger taxa tend to have shorter terminal branch lengths than smaller taxa. This observation suggests that rates of mitochondrial DNA evolution are slower for larger taxa. Rate calibrations based on the fossil record reveal concordant body size effects. We interpret these results as evidence for a metabolic rate effect, as the species in this order exhibit large differences in metabolic rates, which are known to be highly correlated with body mass in this group. Our results support previous findings of body size effects and show that this effect can be significant even within a single avian order. This suggests that even lineage-specific molecular clocks may not be tenable if calibrations involve taxa with different metabolic rates.      

The effects of solutes on the freezing properties of and hydration forces in lipid lamellar phases.

Quantitative deuterium nuclear magnetic resonance is used to study the freezing behavior of the water in phosphatidylcholine lamellar phases, and the effect upon it of dimethylsulfoxide (DMSO), sorbitol, sucrose, and trehalose. When sufficient solute is present, an isotropic phase of concentrated aqueous solution may coexist with the lamellar phase at freezing temperatures. We determine the composition of both unfrozen phases as a function of temperature by using the intensity of the calibrated free induction decay signal (FID). The presence of DMSO or sorbitol increases the hydration of the lamellar phase at all freezing temperatures studied, and the size of the increase in hydration is comparable to that expected from their purely osmotic effect. Sucrose and trehalose increase the hydration of the lamellar phase, but, at concentrations of several molal, the increase is less than that which their purely osmotic effect would be expected to produce. A possible explanation is that very high volume fractions of sucrose and trehalose disrupt the water structure and thus reduce the repulsive hydration interaction between membranes. Because of their osmotic effect, all of the solutes studied reduced the intramembrane mechanical stresses produced in lamellar phases by freezing. Sucrose and trehalose at high concentrations produce a greater reduction than do the other solutes.     

Transient expression of adheron molecules during chick retinal development.

Neuritogenesis and synapse formation are transient phenomena mediated in part by filopodial attachments (Tsui, Lankford, and Klein, Proc. Natl. Acad. Sci. 82:8256-8260 1985). The attachments can be labeled by antisera against adherons, adhesive microparticles isolated from cell culture media (Tsui, Schubert, and Klein, J. Cell Biol. 106:2095-2108 1988). Here, two monoclonal antibodies raised against adherons have been found to recognize transiently expressed membrane antigens of developing avian retina. Early in development, monoclonal antibody (mAb) AD1 stained antigens that spanned the entire tissue. With time, immunoreactivity became restricted to optic fiber, ganglion cell, and inner plexiform layers. Immunoblots of embryonic day (E) 13 retina showed a broad band at 66-72 kD for particulate fractions and a fine band at 70 kD for soluble fractions. The particulate forms disappeared as retinas matured, but the soluble form did not. mAb AD2 initially labeled retina antigens of optic fiber, ganglion cell, and inner plexiform layers (IPL). Labeling in the plexiform layer showed discrete lamina. Immunoreactivity first appeared at E9, peaked at E15, and then disappeared shortly after hatching. In isolated cells, AD2 labeled small cell surface aggregates. Cytoarchitectural studies, using whole-mount transmission electron microscopy, showed AD2 antigen in cell surface microfilaments, including some that joined filopodia together. The adheron antigens recognized by mAbs AD1 and AD2 thus were (1) topographically restricted; (2) associated with cell surfaces; and (3) developmentally down-regulated. This pattern suggests a role in developmentally transient cell surface phenomena, such as neurite extension or junction biogenesis.     

The molecular defect in a family with mild atypical osteogenesis imperfecta and extreme joint hypermobility: Exon skipping caused by an 11-bp deletion from an intron in one COL1A2 allele

Summary We have investigated a family with an autosomal dominantly inherited connective-tissue defect causing extreme joint hypermobility, premature osteoporosis and late-onset fractures. Analysis of collagenous proteins from affected individuals showed a deletion in some 2(I) chains. Peptide mapping localized this to the CB peptide 2CB4, which covers the N-terminal one-third of the protein chain. Polymerase chain reaction amplification and sequencing of cDNA derived from this region of the mRNA identified á heterozygous deletion of the 54 by comprising exon 9. Similar analysis of the genomic DNA revealed an 11-bp deletion from bp3 to bp13 of IVS-9. This disrupts the consensus 5 splice signal (GTAAGT) and leads to exon skipping. In a family study of 13 affected and unaffected family members using both heteroduplex formation and direct analysis for the deletion, all of the affected, but no unaffected individuals, were found to carry the deletion. This generated a positive Lod score of 2.6 with the Liped programme.