Specific glycanforms of type IX collagen accumulate in embryonic chick sterna after 17 days of development

Type IX collagen is a key component of the extracellular matrix of cartilage where it occurs at the surfaces of type II collagen fibrils as a glycanated molecule. The function of the glycosaminoglycan (GAG) side chain of the molecule is, however, unknown. We have shown that type IX collagen in chicken sternal cartilage is synthesized with a unimodal distribution of GAG chain size, but at post 17 days of development three predominant glycanforms of type IX collagen accumulate. Such accumulation did not occur in sterna from day 15 embryos. In day 17 embryos predominant glycanforms were found in the caudal region of the sternum. By day 19 of development the three predominant glycanforms are widespread throughout the caudal and cephalic regions. The results indicate that developmental and anatomical changes occur to type IX collagen that depend on the size of the GAG chain attached to the alpha2(IX) chain of the molecule.      

Prostaglandin F2α induced luteolysis,hypothermia, and abortions in beagle bitches

Luteal phase plasma progesterone was radioimmunoassayed in samples collected before, during, and after a 72 hr treatment period during which Beagle bitches received repeated i.m. injections of prostaglandin F₂α (n=17) or saline (n=3). PGF₂α (20 ug/kg every 8 hr or 30 ug/kg every 12 hr) was administered to 7 pregnant and 8 nonpregnant bitches during the mid or late luteal phase of the cycle (Day 25–58) and to 2 nonpregnant bitches during the early luteal phase (Days 5 and 20). Progesterone was depressed from pretreatment levels (3 – 40 ng/ml) in each of the 15 bitches given PGF₂α after Day 25 of the cycle. Mean progesterone (ng/ml plasma) at ?24, 0, 12, 24, 36, 48, 60, 72 and 96 hr from the initial PGF₂α injection were 16.6, 15.6, 9.3, 5.1, 2.1, 1.5, 1.4, 1.1 and 1.1 (±0.9, n=15). Thereafter, progesterone was nondetectable in the 8 nonpregnant bitches and in 4 pregnant bitches that aborted. Abortions occurred when progesterone was depressed to 0.6 – 1.4 ng/ml, 56–80 hr after starting PGF₂α treatment on Days 33–53 of the cycle. Three pregnant bitches did not abort when progesterone was depressed to a mean low value of 2.1 ng/ml during PGF₂α treatments begun on Day 31 – 40 of pregnancy. Progesterone in these bitches recovered to 5 – 10 ng/ml and was maintained until the normal prepartum decline. Since PGF₂α can induce complete luteolysis it may be of use as an abortifacient in the bitch.A transient fall in rectal temperature occurred in each of 12 luteal phase bitches injected with PGF₂α (20 ug/kg, i.m.). The hypothermia was detectable within 15 min, maximal at 45 – 60 min, and averaged 1.39° C. No temperature changes were noted in eight ovariectomized bitches similarly treated. In six luteal phase bitches, plasma progesterone fell 20–45% within the 15 min required to observe a consistent decline in rectal temperature following PGF₂α administration. The transient hypothermia following PGF₂α appears to be secondary to the luteolytic effect and dependent on a fall in progesterone.     

Ataxia-telangiectasia: linkage analysis of chromosome 11q22-23 markers in Turkish families.

To further pinpoint the location of the genes for ataxia-telangiectasia on the long arm of chromosome 11, we performed linkage analysis and analysis of recombinants of genetic haplotypes on 14 Turkish families with ataxia-telangiectasia, 12 of which were consanguineous. These studies used more than 25 polymorphic genetic markers spanning a region of the long arm of chromosome 11 that is larger than 50 cM. Seven markers gave significant LOD scores to AT: CJ5, DRD2, CJ208, S144, CD3E, PBGD, and S147, as did haplotypes created with pairs of markers DRD2/CJ5 and S144/CJ208, giving recombination fractions (theta) of 0.00, 0.00, 0.05, 0.08, 0.03, 0.09, 0.07, 0.00, and 0.06, respectively. Monte Carlo analysis of these 14 Turkish families indicated the best location for a single AT gene to be within a 6 cM sex-averaged (3 cM male-specific) interval defined by STMY and CJ77; this was three times more likely than the next most likely location (peak III) at the DRD2 locus. The analysis also revealed a peak (peak II) between S147 and S133, which may represent the complementation group D gene. Recombinant analysis of haplotypes also localized an AT locus to the STMY-CJ77 interval. Taken together, these results suggest that at least two distinct AT loci exist (ATA and ATD) at 11q22-23, with perhaps a third locus, ATC, located very near to the ATA gene. This genetic heterogeneity further complicates plans to isolate the major ATA and ATC genes and to begin identifying AT carriers in the general population.     

The ataxia-telangiectasia gene (ATA) on chromosome II is distinct from the ETS-1 gene.

We have studied the segregation of an RFLP detected with a human ETS-1 genomic probe in 25 families containing members affected with ataxia-telangiectasia (AT) and in 27 families from the Centre d'Etude du Polymorphisme Humain (CEPH) panel. We have recently mapped a gene for AT to 11q22-23 by linkage to the markers THY1 and D11S144. Multipoint linkage analysis of the CEPH families indicated that ETS-1 is located on chromosome 11q approximately 19.2 centimorgans telomeric to THY1. Analysis of the segregation of ETS-1 alleles in AT families yields strongly negative LOD scores, excluding an AT gene from a region extending 15 cM to either side of ETS-1. Multipoint mapping of ETS-1, D11S144, THY1, and AT also excludes the possibility that an AT gene is telomeric to ETS-1.     

T-cell receptor genes and insulin-dependent diabetes mellitus (IDDM): no evidence for linkage from affected sib pairs.

Several investigators have reported an association between insulin-dependent diabetes mellitus (IDDM) and an RFLP detected with a probe for the constant region of the beta chain (C beta) of the human T-cell receptor (TCR). A likely hypothesis is that the closely linked TCR variable (V beta) region genes contribute to IDDM susceptibility and that the association with the TCR C beta locus reflects this contribution, via linkage disequilibrium between V beta and C beta. The products of the beta-chain genes might be expected to be involved in the etiology of IDDM because of the autoimmune aspects of IDDM, the known involvement of HLA, and the necessity for TCR and HLA molecules to interact in an immune response. In order to investigate the hypothesis, we tested for linkage between IDDM and V genes encoded at either the TCR beta locus on chromosome 7 or the TCR alpha locus on chromosome 14, using 36 families with multiple affected sibs. No excess sharing of haplotypes defined by V alpha or V beta gene RFLPs was observed in affected sib pairs from IDDM families. We also studied unrelated IDDM patients (N = 73) and controls (N = 45) with the C beta RFLP but were unable to confirm the reported association even when the sample was stratified by HLA-DR type. Our results are incompatible with close linkage, in the majority of families, between either the TCR alpha or TCR beta locus and a gene making a major contribution to susceptibility to IDDM.     

Arabidopsis ATG4 cysteine proteases specificity toward ATG8 substrates

Macroautophagy (hereafter autophagy) is a regulated intracellular process during which cytoplasmic cargo engulfed by double-membrane autophagosomes is delivered to the vacuole or lysosome for degradation and recycling. Atg8 that is conjugated to phosphatidylethanolamine (PE) during autophagy plays an important role not only in autophagosome biogenesis but also in cargo recruitment. Conjugation of PE to Atg8 requires processing of the C-terminal conserved glycine residue in Atg8 by the Atg4 cysteine protease. The Arabidopsis plant genome contains 9 Atg8 (AtATG8a to AtATG8i) and 2 Atg4 (AtATG4a and AtATG4b) family members. To understand AtATG4’s specificity toward different AtATG8 substrates, we generated a unique synthetic substrate C-AtATG8-ShR (citrine-AtATG8-Renilla luciferase SuperhRLUC). In vitro analyses indicated that AtATG4a is catalytically more active and has broad AtATG8 substrate specificity compared with AtATG4b. Arabidopsis transgenic plants expressing the synthetic substrate C-AtAtg8a-ShR is efficiently processed by endogenous AtATG4s and targeted to the vacuole during nitrogen starvation. These results indicate that the synthetic substrate mimics endogenous AtATG8, and its processing can be monitored in vivo by a bioluminescence resonance energy transfer (BRET) assay. The synthetic Atg8 substrates provide an easy and versatile method to study plant autophagy during different biological processes.     

Diversity and ecology of algae from the Nahal Qishon river,northern Israel

In 59 samples of periphyton and phytoplankton collected in 2002 - 2003 from the Nahal Qishon (Qishon River), northern Israel, we found 178 species from seven divisions of algae and cyanoprocaryotes. Diatoms, clorophytes, and cyanoprocaryotes prevail. Nitzschia and Navicula (Bacillariophyta) are the most abundant. Most of the species are cosmopolitan or widespread, except Lagynion janei (Chrysophyta), which is endemic for the Mediterranean Realm. About 17% of species (26) are new for Israel and five of them represent the first recorded genera: Crinalium endophyticum Crow, Actinocyclus normanii (Gregory) Hustedt, Rhizoclonium hieroglyphicum (Agardh) Kütz (Chlorophyta), Lagynion janei Bourelly, and Stylococcus aureus Chodat. Most of them come from a rare riverine assemblage with red alga Audouinella pygmea, as well as from the estuarine assemblage. Alkaliphiles predominate among the indicators of acidity, with few acidophiles confined to the communities under the impact of industrial wastes. Among the indicators of salinity, most numerous are the oligohalobien-indifferents and species adapted to a moderate salinity level. The relative species richness of ecological groups and the indices of saprobity are correlated with changes in conductivity, pH, and N-nitrate concentration. Indicators of organic pollution fall in the range of betameso- to alfamesosaprobic self-purification grades. Our studies show ecological significance of the Nahal Qishon as a model for a strongly disturbed aquatic ecosystem in the coastal zone of eastern Mediterranean.     

Molecular phylogeny of Neotropical bioluminescent beetles (Coleoptera: Elateroidea) in southern and central Brazil

Bioluminescence in beetles is found mainly in the Elateroidea superfamily (Elateridae, Lampyridae and Phengodidae). The Neotropical region accounts for the richest diversity of bioluminescent species in the world with about 500 described species, most occurring in the Amazon, Atlantic rainforest and Cerrado (savanna) ecosystems in Brazil. The origin and evolution of bioluminescence, as well as the taxonomic status of several Neotropical taxa in these families remains unclear. In order to contribute to a better understanding of the phylogeny and evolution of bioluminescent Elateroidea we sequenced and analyzed sequences of mitochondrial NADH2 and the nuclear 28S genes and of the cloned luciferase sequences of Brazilian species belonging to the following genera: (Lampyridae) Macrolampis, Photuris, Amydetes, Bicellonycha, Aspisoma, Lucidota, Cratomorphus; (Elateridae) Conoderus, Pyrophorus, Hapsodrilus, Pyrearinus, Fulgeochlizus; and (Phengodidae) Pseudophengodes, Phrixothrix, Euryopa and Brasilocerus. Our study supports a closer phylogenetic relationship between Elateridae and Phengodidae as other molecular studies, in contrast with previous morphologic and molecular studies that clustered Lampyridae/Phengodidae. Molecular data also supported division of the Phengodinae subfamily into the tribes Phengodini and Mastinocerini. The position of the genus Amydetes supports the status of the Amydetinae as a subfamily. The genus Euryopa is included in the Mastinocerini tribe within the Phengodinae/Phengodidae. Copyright © 2013 John Wiley & Sons, Ltd.