Primate evolution of a human chromosome 1 hypervariable repetitive element

Summary The clone designated hMF #1 represents a clustered DNA family, located on chromosome 1, consisting of tandem arrays displaying a monomeric length of 40 bp and a repetition frequency of approximately 7×10³ copies per haploid genome. The sequence hMF #1 reveals multiple restriction fragment length polymorphisms (RFLPs) when human genomic DNA is digested with a variety of 4–6-bp recognition sequence restriction enzymes (i.e., Taq I, Eco RI, Pst I, etc.). When hamster and mouse genomic DNA was digested and analyzed, no cross-species homology could be observed. Further investigation revealed considerable hybridization in the higher primates (chimpanzee, gorilla, and orangutan) as well as some monkey species.The evolutionary relationship of this repetitive DNA sequence, found in humans, to that of other primates was explored using two hybridization methods: DNA dot blot to establish copy number and Southern DNA analysis to examine the complexity of the RFLPs. Homology to the hMF #1 sequence was found throughout the suborder Anthropoidea in 14 ape and New and Old World monkey species. However the sequence was absent in one species of the suborder Prosimii. Several discrepancies between established evolutionary relationships and those predicted by hMF #1 exist, which suggests that repetitive elements of this type are not reliable indicators of phylogenetic branching patterns. The phenomenon of marked diversity between sequence homologies and copy numbers of dispersed repetitive DNA of closely related species has been observed inDrosophila mice,Galago, and higher primates. We report here a similar phenomenon for a clustered repeat that may have originated at an early stage of primate evolution.     

Prenatal identification of a deleted Y chromosome by cytogenetics and a Y-specific repetitive DNA probe

Summary A very small sex chromosome was identified prenatally as a Y chromosome by using molecular hybridization in conjunction with conventional cytogenetics techniques. The combination of R-banding, Q-banding, distamycin-DAPI staining suggested that the chromosome might be a de novo deletion of the Y chromosome as the father's Y chromosome was normal. Restriction enzyme analysis of amniotic fluid cell DNA using a Y chromosome repetitive probe confirmed the origin of this chromosome.     

Genetic stability of the D1Z2 region: implications for DNA genotyping and paternity testing.

The aim of the present study was to examine a single locus variable number tandem repeat for the purpose of DNA genotyping ("fingerprinting"). DNAs of 175 individuals from five ethnic groups (Black, Chinese, Japanese, Caucasian, and Melanesian) were analyzed. Restriction fragment length polymorphic analysis of random individuals revealed individual specific DNA patterns in all but one group. Among 20 Melanesian inhabitants of the Vanuatu islands in the southwest Pacific, three individuals were found to share a common pattern. This island population represents a "genetic isolate" and illustrates the importance of carrying out population studies on individual ethnic groups of interest. The complexity and the genetic stability of the D1Z2 region as revealed by the probe hMF1 make it an excellent candidate for DNA genotyping in paternity testing as 101 Caucasian individuals each had unique patterns for PstI and SinI digests.     

Irreversible thiophosphorylation and activation of tension in functionally skinned rabbit ileum strips by [35S]ATP gamma S.

Rabbit ileum strips were functionally skinned by exposure to staphylococcal alpha-toxin. Incubation of the strips in the ATP analog ATP gamma S or [35S]ATP gamma S in the presence of Ca2+ (but not in the absence of Ca2+) resulted in a maximal Ca2+-insensitive activated tension that persisted following removal of Ca2+. Correlated with this tension was 35S-labeling of the 20,000-dalton myosin light chain, LC20, that persisted even after removal of Ca2+. Tension in these strips partially relaxed when exposed to ATP (alpha,beta-methylene). In contrast, alpha-toxin-treated strips exposed to ATP or [gamma-32P]ATP showed Ca2+-sensitive, reversible activated tension and reversible 32P-labeling of the LC20. These results are consistent with a currently proposed model of Ca2+ control of smooth muscle contraction involving a myosin light chain kinase-phosphatase system.     

Lung tissue extracellular matrix-derived hydrogels protect against radiation-induced lung injury by suppressing epithelial–mesenchymal transition

This study aimed to examine whether lung tissue extracellular matrix (ECM) hydrogels have protective effects on radiation-induced lung injury (RILI). The cytocompatibility and histocompatibility were tested for the obtained ECM-derived hydrogel. Sprague–Dawley rats were randomly divided into three groups (n = 18): control group (control); rats receiving irradiation and intratracheal injection of normal saline (IR + NS); and rats receiving irradiation and intratracheal injection of lung ECM-derived hydrogel (IR + ECM). The wet/dry weight ratio was used to evaluate the congestion and edema of the lungs. Histopathological analysis of lung tissues was performed using hemotoxylin and eosin staining and Masson's trichrome staining. Immunohistochemical staining and western blot analyses were carried out to determine the expression of epithelial–mesenchymal transition (EMT)-related proteins in lung tissues (E-cadherin, α-smooth muscle actin [α-SMA], and vimentin). In addition, tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1) and interleukin-6 (IL-6), hydroxyproline, malondialdehyde (MDA), and superoxide dismutase (SOD) levels were also evaluated. The ECM-derived hydrogels had good cytocompatibility and histocompatibility. ECM-derived hydrogel treatment improved lung histopathology injury and pulmonary edema. Higher expression of E-cadherin and lower expression of vimentin and α-SMA were found in the IR + ECM group compared with those in the IR + NS group. Hydroxyproline levels were reduced by ECM-derived hydrogel treatment compared with those in the IR + NS group. Obvious increases of TNF-α, IL-6, and TGF-β1 were identified following irradiation. Marked reductions in MDA content and increases in SOD were induced by ECM-derived hydrogel treatment in rats after radiation. ECM-derived hydrogels were shown to protect against RILI, potentially by reducing EMT, inflammation, and oxidative damage.     

Circulating levels of VEGF-A, VEGF-D and soluble VEGF-A receptor (sFIt-1) in human breast cancer

As circulating levels of vascular endothelial growth factor (VEGF-A) are raised in malignancy, the aim of this study was to investigate whether similar changes occur in two related factors, VEGF-D and the soluble VEGF-A receptor FIt-1 (sFIt-1). Circulating levels of VEGF-A, VEGF-D and sFIt-1 were determined by ELISA in 51 patients with primary breast cancer and matched healthy controls. Results were correlated with clinicopathological data. Whilst there was a difference in VEGF-A levels between patient and control groups (p = 0.03), no such difference was observed for sFIt-1 or VEGF-D levels and there was no association between individual factors and the clinicopathological variables examined. However, there was a positive correlation between VEGF-A and sFIt-1 levels in both patient and control groups (p < 0.0001). In addition, the ratio of sFIt-1 to VEGF-A was significantly different between patients and controls (p < 0.0001) and was also associated with tumour size (p = 0.01) within the patient group. During tumour progression there is a change in the relative amounts of sFIt-1 and VEGF-A in the circulation. Measuring the sFIt-1:VEGF-A ratio may have more significance than VEGF-A alone and further studies are needed to determine whether the ratio is of use as a prognostic marker or as a means of monitoring response to anti-angiogenic therapy in cancer.     

Mapping of citrullinated fibrinogen B-cell epitopes in rheumatoid arthritis by imaging surface plasmon resonance

Introduction  

Rheumatoid arthritis (RA) frequently involves the loss of tolerance to citrullinated antigens, which may play a role in pathogenicity. Citrullinated fibrinogen is commonly found in inflamed synovial tissue and is a frequent target of autoantibodies in RA patients. To obtain insight into the B-cell response to citrullinated fibrinogen in RA, its autoepitopes were systematically mapped using a new methodology.     

Evaluation of the enteric microflora of captive whooping cranes (Grus americana) and sandhill cranes (Grus canadensis)

The enteric flora of captive whooping cranes (Grus americana) and sandhill cranes (Grus canadensis) has not been well described, despite its potential importance in the understanding of both the normal condition of the intestinal physiology of these animals and the altered colonization within disease states in these birds. Nineteen whooping cranes and 23 sandhill cranes housed currently at the Calgary Zoo or its affiliated Devonian Wildlife Conservation Centre (DWCC) in Calgary, Alberta were sampled from October 2004–February 2005 by collecting aerobic and anaerobic cloacal swabs from each bird. There were seven major groupings of bacteria isolated from both species of crane. Gram‐positive cocci, coliforms, and gram‐negative bacilli were the most prevalent types of bacteria isolated for both crane species, with Escherichia coli, Enterococcus faecalis, and Streptococcus Group D, not Enterococcus the bacterial species isolated most commonly. There was a significant difference in the average number of isolates per individual between the two crane species but no differences between age or gender categories within crane species. Campylobacter sp. were isolated from five whooping cranes. The potential zoonotic pathogen Campylobacter jejuni was isolated from one whooping crane and C. upsaliensis was isolated from a second. Three other isolates were unspeciated members of the Campylobacter genus and likely belong to a species undescribed previously. The evaluation of the enteric cloacal flora of whooping cranes and sandhill cranes illustrates that differences exist between these two closely related crane species, and highlights the potential implications these differences may have for current practices involving captive wildlife. Zoo Biol 0:1–13, 2007. © 2007 Wiley‐Liss, Inc.