Autosomal STRs Provide Genetic Evidence for the Hypothesis That Tai People Originate from Southern China

Tai people are widely distributed in Thailand, Laos and southwestern China and are a large population of Southeast Asia. Although most anthropologists and historians agree that modern Tai people are from southwestern China and northern Thailand, the place from which they historically migrated remains controversial. Three popular hypotheses have been proposed: northern origin hypothesis, southern origin hypothesis or an indigenous origin. We compared the genetic relationships between the Tai in China and their “siblings” to test different hypotheses by analyzing 10 autosomal microsatellites. The genetic data of 916 samples from 19 populations were analyzed in this survey. The autosomal STR data from 15 of the 19 populations came from our previous study (Lin et al., 2010). 194 samples from four additional populations were genotyped in this study: Han (Yunnan), Dai (Dehong), Dai (Yuxi) and Mongolian. The results of genetic distance comparisons, genetic structure analyses and admixture analyses all indicate that populations from northern origin hypothesis have large genetic distances and are clearly differentiated from the Tai. The simulation-based ABC analysis also indicates this. The posterior probability of the northern origin hypothesis is just 0.04 [95%CI: (0.01–0.06)]. Conversely, genetic relationships were very close between the Tai and populations from southern origin or an indigenous origin hypothesis. Simulation-based ABC analyses were also used to distinguish the southern origin hypothesis from the indigenous origin hypothesis. The results indicate that the posterior probability of the southern origin hypothesis [0.640, 95%CI: (0.524–0.757)] is greater than that of the indigenous origin hypothesis [0.324, 95%CI: (0.211–0.438)]. Therefore, we propose that the genetic evidence does not support the hypothesis of northern origin. Our genetic data indicate that the southern origin hypothesis has higher probability than the other two hypotheses statistically, suggesting that the Tai people most likely originated from southern China.     

Plasmid profiles of Mycobacterium avium complex isolated from swine

Twenty strains of Mycobacterium avium complex (MAC) isolated from swine and five strains from humans were examined for drug susceptibility and plasmid content. Four strains of swine origin and two strains of human origin harbored plasmid DNAs differing in molecular weights. No relationship between plasmid contents and drug resistance was observed. Southern DNA-DNA hybridization showed that small plasmids from swine MAC strains were homologous to those from human origin at the nucleotide level.     

Using parentage analysis to estimate rates of straying and homing in Chinook salmon (Oncorhynchus tshawytscha)

We used parentage analysis based on microsatellite genotypes to measure rates of homing and straying of Chinook salmon (Oncorhynchus tshawytscha) among five major spawning tributaries within the Wenatchee River, Washington. On the basis of analysis of 2248 natural‐origin and 11594 hatchery‐origin fish, we estimated that the rate of homing to natal tributaries by natural‐origin fish ranged from 0% to 99% depending on the tributary. Hatchery‐origin fish released in one of the five tributaries homed to that tributary at a far lower rate than the natural‐origin fish (71% compared to 96%). For hatchery‐released fish, stray rates based on parentage analysis were consistent with rates estimated using physical tag recoveries. Stray rates among major spawning tributaries were generally higher than stray rates of tagged fish to areas outside of the Wenatchee River watershed. Within the Wenatchee watershed, rates of straying by natural‐origin fish were significantly affected by spawning tributary and by parental origin: progeny of naturally spawning hatchery‐produced fish strayed at significantly higher rates than progeny whose parents were themselves of natural origin. Notably, none of the 170 offspring that were products of mating by two natural‐origin fish strayed from their natal tributary. Indirect estimates of gene flow based on F_ST statistics were correlated with but higher than the estimates from the parentage data. Tributary‐specific estimates of effective population size were also correlated with the number of spawners in each tributary.     

Infectivity of Histomonas meleagridis of Cecal and Liver Origins Compared

SYNOPSIS. Turkey poults were inoculated rectally with 100, 1000, 10,000, or 100,000 Histomonas meleagridis from the ceca of a group of experimentally infected turkeys. Other poults were given the same numbers of histomonads from an infected liver from the same group of source birds, Comparisons of the incidence of infection, liver involvement, mortality, and average survival time following these inoculations showed that organisms of cecal origin were about 100 times more effective in producing histomoniasis than were organisms of liver origin. It is suggested that this difference in infectivity resulted from heavy losses of histomonads of liver origin that were due to various selective processes.     

Analysis of features contributing to activity of the single-stranded origin of Bacillus plasmid pBAA1.

The features which contribute to the activity of the single-stranded origin of the Bacillus plasmid pBAA1 were investigated. This origin is contained on a DNA fragment greater than 116 but less than 191 bases in size. There is the potential to form three stem-loop structures within this fragment. Comparison of the sequence of this origin from pBAA1 with the sequence of a homologous fragment from the Bacillus thuringiensis plasmid pGI2 indicates that both the structure and the relative positioning of the predicted stem-loops are important for origin activity. Deletion analysis suggests that it is the structure of stem-loop III which is important, because it can be replaced by a nonrelated dyad element without significant loss of origin activity. Three sequence motifs are conserved between the origins from pBAA1 and pGI2. Mutation of motif 1 leads to attenuation of single-stranded origin activity. A second motif (motif 3) shares significant homology with a group of single-strand initiation (ssi) sites found on plasmids isolated from Escherichia coli, suggesting that it also contributes to single-stranded origin activity. Our results also indicate that RNA polymerase is utilized to synthesize the RNA primer at the pBAA1 single-stranded origin and that this origin can function in both Bacillus subtilis and Staphylococcus aureus.     

大肠杆菌中整合状态的F′质粒复制起点的克隆和分析

用标记获救法克隆了整合状态的F′质粒的复制起点,证明了由这一复制起点构成的mini-F质粒在不亲和性和对吖啶橙的敏感性方面和自主状态的F′质粒都没有不同。对这一复制起点和来自自主状态的F质粒的复制起点进行了亚克隆,并作限制性内切酶酶切分析比较,没有发现两者在结构上有差异。本文的结果提示,F质粒和F′质粒在发动染色体复制中对recA基因的依赖性的不同,可能与质粒整合在染色体上的位置不同有关。     

Isolation of saprophytic Microsporum praecox Rivalier from sites associated with horses

Several M. praecox isolates of saprophytic origin were obtained in Belgium from horses and their surroundings. Visualization of macroconidia in dust collected in stables proved its saprophytic origin. A few strains were obtained from human cases of tinea corporis.     

Incidence of anomalous origin of coronary artery in 1879 Chinese adults on dual-source CT angiography

Background and Objective. Dual-source CT (DSCT) has been used to detect coronary artery anomalies. The purpose of this study was to assess the incidence of anomalous origin of the coronary artery in Chinese adults. Methods. We summarised all patients who underwent DSCT coronary angiography (CTCA) from December 2006 to February 2008, and data of anomalous origin of the coronary artery in Chinese adults were recorded. Results. 1879 patients underwent CTCA during that period; 24 patients with an anomalous origin of the coronary artery were detected, giving an incidence of 1.3%. Fifteen patients had an anomalous origin of the right coronary artery (12 from left coronary sinus, 3 high takeoff), eight patients had an anomalous origin of the left coronary artery (LCA from posterior sinus of Valsalva in three cases, LCX from the right coronary sinus, LCX from RCA, high takeoff, LCA from right coronary sinus, and single coronary artery in one case, respectively), and one patient had an anomalous origin of both coronary arteries (high takeoff). Conclusion. The incidence of anomalous origin of the coronary artery in Chinese adults in this study is 1.3%. DSCT can clearly visualise the anomalous origin and course of the coronary artery and is a useful screening modality. (Neth Heart J 2010;18:466-70.)     

A search for a paternal-age effect upon cases of 47, +21 in which the extra chromosome is of paternal origin

If there is a paternal-age effect for 47, +21, it would appear most likely to be present primarily, if not exclusively, in cases in which the extra chromosome is of paternal origin. To search for such an effect, data were reviewed from seven series reporting at least four cases of 47, +21 of paternal origin. The mean of the paternal age-maternal-age difference of such cases (dp) in each series was compared with the mean of the paternal-age differences of cases in the same series that were of maternal origin (dm). If the difference between these (dp - dm or delta) is greater than zero, then this would imply a positive paternal-age effect among cases of paternal origin, at least compared to those of maternal origin. In the seven series, the values of delta ranged from -2.2 years to +3.4 years, and there was no evidence in these comparisons for any consistent trend. A second analysis controlled for any effect of maternal-age variation upon this difference. Each case of paternal origin was matched with a case of maternal origin in the same series that was of the same maternal age. Of 60 cases of paternal origin, exact matches were found for 38. In these 38, the mean value of the difference in parental ages, dp - dm or delta, was negative, about -1.1 (+/- 5.1 years). The difference was highest for the nine cases of paternal origin in which the extra chromosome resulted from presumptive second-division non-disjunction, -1.8 (+/- 3.8 years).(ABSTRACT TRUNCATED AT 250 WORDS)     

The repeated sequences (incB) preceding the protein E gene of plasmid mini-F are essential for replication

Summary At the XhoI site (45.08F) of plasmid mini-F a deletion of 649 bp was generated employing exonuclease Bal31. By this deletion nucleotide sequences functioning as origin II and the four 19 bp direct repeats constituting the incB region in front of the E protein gene were removed from the plasmid. Analysis of proteins radioactively labelled in Escherichia coli mini-cells indicated that all mini-F encoded proteins are expressed. However, the plasmid carrying the deletion was not capable of replicating from the primary origin (origin I, 42.6F). Recently a smaller deletion at the XhoI site (45.08F) of about 300 bp, removing only the region functioning as origin II and replicating from origin I, was described by Tanimoto and Iino (1984, 1985). The data presented suggest that the incB repeats are essential for the initiation of replication from origin I, and possibly also from origin II, and seem not to be engaged in the autoregulation of E protein expression.     

Studies on the role of the phi X174 gene A protein in phi X174 viral strand synthesis. III. Replication of DNA containing two viral replication origins

Supercoiled plasmid bearing two wild-type phi X origin sequences on the same strand supported the phi X A protein-dependent in vitro formation of two smaller single-stranded circles, the lengths of which were equivalent to the distance between the two origins. Additional double origin plasmids were utilized to determine whether origins defective in the initial nicking event (initiation) could support circularization (termination). In all cases tested, the presence of a mutant origin on the same strand with a wild-type origin affected the level of replication in a manner consistent with the previously determined activity of the mutant origin. When a functional mutant origin was present on the same strand as a wild-type origin, the efficiency of replication and the DNA products formed were almost identical to those of the plasmid containing two wild-type origins. Plasmid DNA bearing both a wild-type origin and a mutant origin that did not support phi X A protein binding or nicking activity, on the other hand, supported efficient DNA synthesis of only full-length circular products, indicating that the origin defective for initiation was incapable of supporting termination. In contrast, the presence of a wild-type origin and an origin that did bind the phi X A protein but was not cleaved resulted in a marked decrease in DNA synthesis along with the production of only full-length products. This suggests that the phi X A protein stalls when it encounters a sequence to which it can bind but cannot cleave. Replication of double origin plasmids containing one functional phi X origin on each strand of the supercoiled DNA was also examined. With such templates, synthesis from the wild-type origin predominated, indicating preferential cleavage of the intact origin sequence. Replication of such substrates also produced a number of aberrant structures, the properties of which suggested that interstrand exchange of the phi X A protein had occurred.     

Spontaneous cytotoxicity of human lymphoblast cell lines mediated by normal peripheral blood lymphocytes. I. Differential susceptibility of T-versus B-cell lines.

Human lymphoblast cell lines of B- and T-cell origin have been tested for their ability to serve as targets in a 4-hr ⁵¹Cr release microcytotoxicity assay using normal human peripheral blood lymphocytes as effector cells. Cell lines of T-cell origin were susceptible to lysis in this assay by effector lymphocytes from all normal donors tested. Cell lines of B-cell origin were repeatably lysed by normal lymphocytes from some, but not all donors. Spontaneous cytotoxicity of B-cell lines, when observed, was also quantitatively less than was obtained using T-cell lines as targets. One cell line (RPMI-7666), of B-cell origin, was not susceptible to spontaneous cytotoxicity by almost all of the normal lymphocyte effectors tested. Lymphocytes from patients with acute lymphoblastic leukemia in remission were less capable of effecting lysis in this assay.     

RecQ4 promotes the conversion of the pre-initiation complex at a site-specific origin for DNA unwinding in Xenopus egg extracts

Eukaryotic DNA replication is initiated through stepwise assembly of evolutionarily conserved replication proteins onto replication origins, but how the origin DNA is unwound during the assembly process remains elusive. Here, we established a site-specific origin on a plasmid DNA, using in vitro replication systems derived from Xenopus egg extracts. We found that the pre-replicative complex (pre-RC) was preferentially assembled in the vicinity of GAL4 DNA-binding sites of the plasmid, depending on the binding of Cdc6 fused with a GAL4 DNA-binding domain in Cdc6-depleted extracts. Subsequent addition of nucleoplasmic S-phase extracts to the GAL4-dependent pre-RC promoted initiation of DNA replication from the origin, and components of the pre-initiation complex (pre-IC) and the replisome were recruited to the origin concomitant with origin unwinding. In this replication system, RecQ4 is dispensable for both recruitment of Cdc45 onto the origin and stable binding of Cdc45 and GINS to the pre-RC assembled plasmid. However, both origin binding of DNA polymerase α and unwinding of DNA were diminished upon depletion of RecQ4 from the extracts. These results suggest that RecQ4 plays an important role in the conversion of pre-ICs into active replisomes requiring the unwinding of origin DNA in vertebrates.     

Origin of plantlets and callus obtained from chile pepper anther cultures

Summary Androgenesis occurred from chile pepper (Capsicum annuum L.) anthers incubated in a continuous warm environment (29° C) with continuous light. Forty plantes and embryoids were retrieved from anther cultures and anllyzed for isozyme markers. Of these, 35 exhibited a single allele for markers suggesting microspore origin, while 5 were heterozygous indicating somatic tissue origin. Chromosome numbers were confirmed for 21 plantlets, of which 16 were haploid and 5 were diploid. However, two plants exhibited a single allele for an isozyme marker but possessed the diploid chromosome number, suggesting spontaneous doubling. Anther cultures also produced callus. Nearly 92% of the slow-growing calli sampled were heterozygous for the isozyme marker, suggesting somatic tissue origin. More than 46% of the fast-growing calli exhibited only one allele for the marker, indicating microspore origin. Callus did not regenerate plantlets. The occurrence of both heterozygous and homozygous diploid plantlets from pepper anther cultures has important implications for applied breeding programs.     

Parental and chromosomal origin of unbalanced de novo structural chromosome abnormalities in man

We report the parental origin, and where possible the chromosomal origin of 115 de novo unbalanced structural chromosome abnormalities detectable by light microscopy. These consisted of 39 terminal deletions, 35 interstitial deletions, 8 rings, 12 duplications and 21 unbalanced translocations. In all categories the majority of abnormalities were of paternal origin, although the proportions varied from a high of 84% in the interstitial deletions and rings to a low of 58% in the duplications. Among the interstitial deletions and duplications, there were approximately equal numbers of intra- and interchromosomal abnormalities, while the majority of unbalanced translocations were isodisomic for the duplicated chromosome. The examination of the parental ages in the four main classes of abnormality showed terminal deletions of maternal origin to be associated with a significantly reduced maternal age. Thus, there is a clear propensity for structural chromosome abnormalities to occur in male germ cells, although the chromosomal origin seems similar irrespective of the parental origin.     

The origin of genes could be polyphyletic

The paradigm of the monophyletic origin of genes is deeply rooted in us all. For instance, this stems from the observation that the possibility of obtaining a good multiple alignment using the same protein from organisms from the three domains of life (Bacteria, Archaea and Eukarya) would seem to imply that the last universal common ancestor (LUCA) must have had that protein and, therefore, the origin of that gene must necessarily be monophyletic. The hypothesis of a polyphyletic origin of genes has to explain how it was possible to evolve highly conserved regions of multiple alignments of orthologous proteins from the three domains of life when these regions clearly seem to define a monophyletic origin of genes. If mRNAs were assembled at the stage of the LUCA through the trans-splicing of pieces of RNA representing mini-genes, and the translation of these mRNAs resulted in proteins whose genes (DNA) actually only evolved much later, i.e. only after the main domains of life were established, then this would explain why multiple alignments of orthologous proteins can be obtained from the three domains of life. Therefore, this makes these multiple alignments compatible with a polyphyletic origin of genes. I have analysed many multiple alignments of orthologous proteins from the three domains of life, reaching a conclusion that seems to suggest that these alignments are also compatible with a polyphyletic origin of genes because, for instance, they contain protein motifs characterising the domains of life. These motifs, and also genes, might have evolved late on, thus making their polyphyletic origin likely.     

QF-PCR examination of parental and meiotic origin of trisomy 21 in Central and Eastern Europe.

Study of parental/meiotic origin of free trisomy 21 in nuclear families from Russia (70 cases), Ukraine (32 cases), and 22 from Germany revealed maternal nondisjunction in 77.3% (Germany), 93.8% (Ukraine), and 91.4% (Russia), paternal origin in 13.6%, 6.2%, and 8.6%, respectively. Maternal meiosis I errors were found in 84.4% (Ukraine), 77.1% (Russia), paternal origin in 3.1% (Ukraine), 2.9% (Russia). Maternal meiosis II errors occurred in 9.4% and 14.3% and paternal in 3.1% and 5.7% in Ukraine and Russia, respectively. No significant differences were found in maternal/paternal origin among Ukraine, Russia, Germany, and published data from other European regions.     

Proteomic characterisation of Echinococcus granulosus hydatid cyst fluid from sheep, cattle and humans

The hydatid cyst fluid (HCF) of Echinococcus granulosus is a complex biological mixture containing a wide range of proteins of both parasite and host origin. Using a combination of in- and off-gel protein fractionation techniques and tandem mass spectrometry 130 HCF proteins were identified from fertile cysts of sheep and human origin and infertile cysts from cattle. Forty-eight proteins were of parasite origin including Antigen 5 and Antigen B--the most abundant parasite proteins, thioredoxin, low-density lipoprotein receptors, cyclophilin and ferritin. Across the three host species the identified HCF proteins were broadly similar although, based on spectral counts, three proteins, including an antigen B isoform, were more abundant in sheep HCF compared with the fluids of cattle and human origin. Eighty-two host proteins were identified in HCF from the three species. Host plasma proteins were the most abundant, although approximately thirty of the host proteins that were identified are not considered constituents of plasma. The identification of parasite heat shock proteins and annexin A13 exclusively in infertile cysts, along with an increased spectral count for cathepsin B, supports the hypothesis of increased cellular stress and apoptosis as the cause of their infertility.     

Deoxyribonucleic Acid-Deoxyribonucleic Acid Hybridization Assay for Replication Origin Deoxyribonucleic Acid of Escherichia coli

Deoxyribonucleic acid (DNA)-DNA hybridization on nitrocellulose filters can be used to assay for replication origin DNA from Escherichia coli if the DNA attached to the filters is enriched for the replication origin sequences. Such DNA can be readily isolated from very rapidly growing cells. When low amounts of this DNA were attached to filters, radioactively labeled DNA from the replication origin hybridized 1.7 times as well as radioactive replication terminus DNA. Under identical conditions, radioactively labeled DNA from exponentially growing cells hybridized only 1.3 times as well as radioactive replication terminus DNA. The replication origin, replication terminus, and randomly labeled DNA hybridized with similar efficiencies to filters containing DNA isolated from cells incubated in the absence of required amino acids. This DNA appeared to have all sequences present at equal frequencies. The hybridization assay was used to demonstrate that the DNA synthesized shortly after the addition of amino acids to cells previously deprived of required amino acids was primarily from the replication origin and then rapidly became similar to DNA synthesized by exponentially growing cells.     

Isolation and characterization of a rolling-circle-type plasmid from Rhodococcus erythropolis and application of the plasmid to multiple-recombinant-protein expression

We isolated, sequenced, and characterized the cryptic plasmid pRE8424 from Rhodococcus erythropolis DSM8424. Plasmid pRE8424 is a 5,987-bp circular plasmid; it carries six open reading frames and also contains cis-acting elements, specifically a single-stranded origin and a double-stranded origin, which are characteristic of rolling-circle-replication plasmids. Experiments with pRE8424 derivatives carrying a mutated single-stranded origin sequence showed that single-stranded DNA intermediates accumulated in the cells because of inefficient conversion from single-stranded DNA to double-stranded DNA. This result indicates that pRE8424 belongs to the pIJ101/pJV1 family of rolling-circle-replication plasmids. Expression vectors that are functional in several Rhodococcus species were constructed by use of the replication origin from pRE8424. We previously reported a cryptic plasmid, pRE2895, from R. erythropolis, which may replicate by a theta-type mechanism, like ColE2 plasmids. The new expression vectors originating from pRE8424 were compatible with those derived from pRE2895. Coexpression experiments with these compatible expression vectors indicated that the plasmids are suitable for the simultaneous expression of multiple recombinant proteins.