Patterns of paternal care in primates

An interspecific comparison was carried out to understand better the relationships among paternal care, paternal certainty, and reproductive burden in primates. Although monogamy is generally rare among mammals, a number of primate species are monogamous. Extensive paternal care is a related issue but is one that is not necessarily associated with monogamy or with paternal certainty. For example, despite paternal certainty, primate mothers in monogamous species with body weights over 2 kg still remain the primary infant caretakers, while males in the communally breeding tamarins carry infants more frequently than mothers do, even in the absence of paternal certainty. Several different tactics are used by small-bodied primates to cope with the energetic burden of raising proportionately large infants in an arboreal environment: (1) infant carrying by subadult and/or related nulliparous females (Saimiri, Lemur monogoz); (2) infant carrying by fathers and offspring (Aotus, Callicebus, Saguinus, Cebuella, Leontopithecus); (3) parking infants while family members forage (Tarsius, Galago, Microcebus, Cheirogaleus, Varecia); or (4) some combination of the above (Callithrix, Hapalemur, Loris). Lactation length and infant growth patterns appear to influence which of these tactics is employed by a given species. Moreover, although most small-bodied, mated, monogamous female primates spend no more than 9 months annually in gestation and lactation,Aotus andCallicebus mated females are either pregnant or lactating on a year-round basis. It is this heavy female reproductive burden that may be an important factor in selection for extensive paternal care in these monogamous cebids.     

Processing and transfer of epidermal growth factor in developing rat jejunum and ileum

Using everted sac technique we demonstrated the transfer of ¹²⁵I-mEGF across the jejunal and ileal walls of suckling, weanling and adult rats. The transfer by the suckling rat jejunum and ileum was significantly inhibited by the presence of dinitrophenol and sodium azide or by the replacement of sodium with potassium or choline. RP-HPLC analysis detected carboxy-terminal processing of ¹²⁵I-mEGF in suckling and adult rat jejunum and ileum. Suckling rat jejunum produced ¹²⁵I-des(53)mEGF and ¹²⁵I-des(49–53)mEGF, whereas ¹²⁵I-des(48–53)mEGF was detected in suckling rat ileum or adult rat jejunum and ileum. All three forms of ¹²⁵I-mEGF bound to anti-EGF antibody and EGF receptors. The receptor binding of ¹²⁵I-des(53)mEGF was higher than that of ¹²⁵I-mEGF, but those of ¹²⁵-des(49–53)mEGF and ¹²⁵I-des(48–53)mEGF were greatly diminished. Results indicate a carboxy-terminal processing of mouse EGF during uptake and transfer in the small intestine of developing and adult rats, and the resulting products showed altered receptor binding. An identical amino acid sequence of the C-terminal pentapeptide of EGF from mouse, human and possibly rat may suggest a biological significance of C-terminal processing of EGF in the small intestine.     

Increased Neural Cell Adhesion Molecule in the CSF of Patients with Mood Disorder

Abstract: Neural cell adhesion molecule (N-CAM) is involved in cell-cell interactions during synaptogenesis, morphogenesis, and plasticity of the nervous system. Disturbances in synaptic restructuring and neural plasticity may be related to the pathogenesis of several neuropsychiatric diseases, including mood disorders and schizophrenia. Disturbances in brain cellular function may alter concentrations of N-CAM in the CSF. Soluble human N-CAM proteins are detectable in the CSF but are minor constituents of serum. We have recently found an increase in N-CAM content in the CSF of patients with schizophrenia. Although the pathogenesis of both schizophrenia and mood disorders is unknown, ventriculomegaly, decreased temporal lobe volume, and subcortical structural abnormalities have been reported for both disorders. We have therefore measured N-CAM concentrations in the CSF of patients with mood disorder. There were significant increases in amounts of N-CAM immunoreactive proteins, primarily the 120-kDa band, in the CSF of psychiatric inpatients with bipolar mood disorder type I and recurrent unipolar major depression. There were no differences in bipolar mood disorder type II patients as compared with normals. There were no significant effects of medication treatment on N-CAM concentrations. It is possible that the 120-kDa N-CAM band present in the CSF is derived from CNS cells as a secreted soluble N-CAM isoform. Our results suggest the possibility of latent state-related disturbances in N-CAM cellular function, i.e., residue from a previous episode, or abnormal N-CAM turnover in the CNS of patients with mood disorder.     

A new transmembrane 4 superfamily molecule in the nematode,Caenorhabditis elegans

Transmembrane 4 superfamily (TM4SF) molecules are predominantly mammalian cell surface glycoproteins that are thought to transduce signals mediating cell development, activation, and motility. Analysis of the Genpept sequence database reveals YKK8, a novel member of the TM4SF in the nematode,Caenorhabditis elegans. YKK8 is a putative 27.4-kDa protein encoded by a gene on chromosome III of theC. elegans genome (Wilson et al. [1994]Nature 368:32–38). The assignment of YKK8 to the TM4SF is justified by three criteria: statistical comparison of protein sequences, conserved TM4SF protein sequence motifs, and conserved TM4SF intron/exon boundaries in the genomic sequence. The discovery of a TM4SF molecule in the nematode extends this superfamily to a more primitive branch of the phylogenetic tree and suggests a fundamental role for TM4SF molecules in biology. Correspondence to: M.G. Tomlinson     

Expression of c-Fos in subcutaneous adipose tissue of the fetal pig

Calcium oxalate crystal growth and aggregation leads to the formation of renal calculi. It is known to be inhibited by several compounds both in vitro and in vivo conditions. The present study highlights the inhibitory potential of sodium pentosan polysulphate (SPP), a semi-synthetic glycosaminoglycan (GAG) on calcium oxalate crystal growth in vitro. Its efficacy was compared with those of known inhibitors like pyrophosphate, heparin and chondroitin-4-sulphate. Of the above compounds pyrophosphate was found to be the most potent inhibitor. Among the GAGs, SPP exhibited 80% inhibitory activity as compared to heparin. A lesser degree of inhibition was observed with chondroitin-4-sulphate.     

Influence of chlorobenzoates on the utilisation of chlorobiphenyls and chlorobenzoate mixtures by chlorobiphenyl/chlorobenzoate-mineralising hybrid bacterial strains

Chlorobenzoates (CBA) arise as intermediates during the degradation of polychlorinated biphenyls (PCBs) and some chlorinated herbicides. Since PCBs were produced as complex mixtures, a range of mono-, di-, and possibly trichloro-substituted benzoates would be formed. Chlorobenzoate degradation has been proposed to be one of the rate-limiting steps in the overall PCB-degradation process. Three hybrid bacteria constructed to have the ability to completely mineralise 2-, 3-, or 4-monochlorobiphenyl respectively, have been studied to establish the range of mono- and diCBAs that can be utilised. The three strains were able to mineralise one or more of the following CBAs: 2-, 3-, and 4-monochlorobenzoate and 3,5-dichlorobenzoate. No utilisation of 2,3-, 2,5-, 2,6-, or 3,4-diCBA was observed, and only a low concentration (0.11 mM) of 2,4-diCBA was mineralised. When the strain with the widest substrate range (Burkholderia cepacia JHR22) was simultaneously supplied with two CBAs, one that it could utilise plus one that it was unable to utilise, inhibitory effects were observed. The utilisation of 2-CBA (2.5 mM) by this strain was inhibited by 2,3-CBA (200 M) and 3,4-CBA (50 M). Although 2,5-CBA and 2,6-CBA were not utilised as carbon sources by strain JHR22, they did not inhibit 2-CBA utilisation at the concentrations studied, whereas 2,4-CBA was co-metabolised with 2-CBA. The utilisation of 2-, 3-, and 4-chlorobiphenyl by strain JHR22 was also inhibited by the presence of 2,3- or 3,4-diCBA. We conclude that the effect of the formation of toxic intermediates is an important consideration when designing remediation strategies.Abbreviations PCB Polychlorinated biphenyl - CBA Chlorobenzoate     

A high frequency of distinct ATM gene mutations in ataxia-telangiectasia.

The clinical features of the autosomal recessive disorder ataxia-telangiectasia (AT) include a progressive cerebellar ataxia, hypersensitivity to ionizing radiation, and an increased susceptibility to malignancies. Epidemiological studies have suggested that AT heterozygotes may also be at increased risk for malignancy, possibly as a consequence of radiation exposure. A gene mutated in AT patients (ATM) has recently been isolated, making mutation screening in both patients and the general population possible. Because of the relatively large size of the ATM gene, the design of screening programs will depend on the types and distribution of mutations in the general population. In this report, we describe 30 mutations identified in a panel of unrelated AT patients and controls. Twenty-five of the 30 were distinct, and most patients were compound heterozygotes. The most frequently detected mutation was found in three different families and had previously been reported in five others. This corresponds to a frequency of 8% of all reported ATM mutations. Twenty-two of the alterations observed would be predicted to lead to protein truncation at sites scattered throughout the molecule. Two fibroblast cell lines, which displayed normal responses to ionizing radiation, also proved to be heterozygous for truncation mutations of ATM. These observations suggest that the carrier frequency of ATM mutations may be sufficiently high to make population screening practical. However, such screening may need to be done prospectively, that is, by searching for new mutations rather than by screening for just those already identified in AT families.