Molecular phylogenetics at the population/species interface in cave spiders of the southern Appalachians (Araneae:Nesticidae:Nesticus)

This paper focuses on the relationship between population genetic structure and speciation mechanisms in a monophyletic species group of Appalachian cave spiders (Nesticus). Using mtDNA sequence data gathered from 256 individuals, I analyzed patterns of genetic variation within and between populations for three pairs of closely related sister species. Each sister-pair comparison involves taxa with differing distributional and ecological attributes; if these ecological attributes are reflected in basic demographic differences, then speciation might proceed differently across these sister taxa comparisons. Both frequency-based and gene tree analyses reveal that the genetic structure of the Nesticus species studied is characterized by similar and essentially complete population subdivision, regardless of differences in general ecology. These findings contrast with results of prior genetic studies of cave-dwelling arthropods that have typically revealed variation in population structure corresponding to differences in general ecology. Species fragmentation through both extrinsic and intrinsic evolutionary forces has resulted in discrete, perhaps independent, populations within morphologically defined species. Large sequence divergence values observed between populations suggest that this independence may extend well into the past. These patterns of mtDNA genealogical structure and divergence imply that species as morphological lineages are currently more inclusive than basal evolutionary or phylogenetic units, a suggestion that has important implications for the study of speciation mechanisms.      

Antagonism between Cry1Ac1 and Cyt1A1 toxins of bacillus thuringiensis

Most strains of the insecticidal bacterium Bacillus thuringiensis have a combination of different protoxins in their parasporal crystals. Some of the combinations clearly interact synergistically, like the toxins present in B. thuringiensis subsp. israelensis. In this paper we describe a novel joint activity of toxins from different strains of B. thuringiensis. In vitro bioassays in which we used pure, trypsin-activated Cry1Ac1 proteins from B. thuringiensis subsp. kurstaki, Cyt1A1 from B. thuringiensis subsp. israelensis, and Trichoplusia ni BTI-Tn5B1-4 cells revealed contrasting susceptibility characteristics. The 50% lethal concentrations (LC50s) were estimated to be 4,967 of Cry1Ac1 per ml of medium and 11.69 ng of Cyt1A1 per ml of medium. When mixtures of these toxins in different proportions were assayed, eight different LC50s were obtained. All of these LC50s were significantly higher than the expected LC50s of the mixtures. In addition, a series of bioassays were performed with late first-instar larvae of the cabbage looper and pure Cry1Ac1 and Cyt1A1 crystals, as well as two different combinations of the two toxins. The estimated mean LC50 of Cry1Ac1 was 2.46 ng/cm2 of diet, while Cyt1A1 crystals exhibited no toxicity, even at very high concentrations. The estimated mean LC50s of Cry1Ac1 crystals were 15.69 and 19.05 ng per cm2 of diet when these crystals were mixed with 100 and 1,000 ng of Cyt1A1 crystals per cm2 of diet, respectively. These results indicate that there is clear antagonism between the two toxins both in vitro and in vivo. Other joint-action analyses corroborated these results. Although this is the second report of antagonism between B. thuringiensis toxins, our evidence is the first evidence of antagonism between toxins from different subspecies of B. thuringiensis (B. thuringiensis subsp. kurstaki and B. thuringiensis subsp. israelensis) detected both in vivo and in vitro. Some possible explanations for this relationship are discussed.     

Cytoplasmic dynein could be key to understanding neurodegeneration

A new mouse mutation, Sprawling, highlights an essential role for the dynein heavy chain in sensory neuron function, but it lacks the ability of other known heavy-chain mutations to ameliorate neurodegeneration due to defective superoxide dismutase.     

Comparison of electroejaculation and transrectal massage for semen collection in range and yearling feedlot beef bulls

Two experiments were conducted to compare electroejaculation (EE) and transrectal massage (RM) of the ampullary region for semen collection from beef bulls, and to determine the effect of semen collection method on semen traits. In experiment 1, semen was collected either by EE or RM randomly assigned on an alternate basis in 137 range beef bulls unaccustomed to being handled. The maximum time allowed for RM was 4 min and if no semen was obtained, EE was used. In experiment 2, semen was collected from 39 yearling feedlot beef bulls that were accustomed to being handled, by RM followed immediately by EE. The maximum time allowed for semen collection by both methods was 4 min. In both experiments, sperm concentration, percent of progressively motile sperm, percent of sperm staining alive, and sperm morphology were determined. In experiment 1, RM resulted in fewer (P<0.001) successful semen collections and fewer bulls with penile protrusion than EE (80.9% versus 100% and 54.4% versus 91.5%, respectively). The success of RM was not influenced by bull age or breed, or by the veterinarian performing the massage. Transrectal massage required more time (30s, P<0.001) for obtaining a semen sample and resulted in samples with lower sperm concentration (P<0.001), percent motile sperm (P<0.05) and percent live sperm (P<0.001) when compared to EE. In experiment 2, EE and RM were equally effective for obtaining a semen sample (97.4 and 94.9%, respectively), but the proportion of bulls exhibiting penile protrusion during semen collection was lower (P<0.0001) with RM compared to EE. Percent of sperm staining alive was also lower (P<0.01) in samples collected by RM. Sperm morphology (normal sperm, head defects, midpiece defects, proximal cytoplasmic droplets, and detached sperm heads) did not differ between samples collected by EE and RM. In conclusion, semen could be collected by transrectal massage from approximately 80% of range beef bulls and from 95% of yearling beef bulls accustomed to handling. Sperm morphology was not affected by the method of semen collection, but percent of motile sperm and live sperm were lower in samples collected by RM. A reduced ability to stimulate penile protrusion with RM precluded examination of the penis in a large proportion of bulls.     

Interleukin-23 is critical for full-blown expression of a non-autoimmune destructive arthritis and regulates interleukin-17A and RORγt in γδ T cells

Introduction

A protein analysis using a mass spectrometry indicated that there are serum proteins showing significant quantitative changes after the administration of infliximab. Among them, connective tissue growth factor (CTGF) seems to be related to the pathogenesis of rheumatoid arthritis (RA). Therefore, this study was conducted to investigate how CTGF is associated with the disease progression of RA.

Methods

Serum samples were collected from RA patients in active or inactive disease stages, and before or after treatments with infliximab. CTGF production was evaluated by ELISA, RT-PCR, indirect immunofluorescence microscopy, and immunoblotting. Osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase (TRAP) staining, a bone resorption assay and osteoclasts specific catalytic enzymes productions.

Results

The serum concentrations of CTGF in RA were greater than in normal healthy controls and disease controls. Interestingly, those were significantly higher in active RA patients compared to inactive RA patients. Furthermore, the CTGF levels significantly were decreased by infliximab concomitant with the disease amelioration. In addition, tumour necrosis factor (TNF)α can induce the CTGF production from synovial fibroblasts even though TNFα can oppositely inhibit the production of CTGF from chondrocytes. CTGF promoted the induction of the quantitative and qualitative activities of osteoclasts in combination with M-CSF and receptor activator of NF-κB ligand (RANKL). In addition, we newly found integrin αVβ3 on the osteoclasts as a CTGF receptor.

Conclusions

These results indicate that aberrant CTGF production induced by TNFα plays a central role for the abnormal osteoclastic activation in RA patients. Restoration of aberrant CTGF production may contribute to the inhibition of articular destruction in infliximab treatment.     

Increased malignancy of Neu-induced mammary tumors overexpressing active transforming growth factor beta1

To determine if Neu is dominant over transforming growth factor beta (TGF-beta), we crossed mouse mammary tumor virus (MMTV)-Neu mice with MMTV-TGF-beta1(S223/225) mice expressing active TGF-beta1 in the mammary gland. Bigenic (NT) and Neu-induced mammary tumors developed with a similar latency. The bigenic tumors and their metastases were less proliferative than those occurring in MMTV-Neu mice. However, NT tumors exhibited less apoptosis and were more locally invasive and of higher histological grade. NT mice exhibited more circulating tumor cells and lung metastases than Neu mice, while NT tumors contained higher levels of phosphorylated (active) Smad2, Akt, mitogen-activated protein kinase (MAPK), and p38, as well as vimentin content and Rac1 activity in situ than tumors expressing Neu alone. Ex vivo, NT cells exhibited higher levels of P-Akt and P-MAPK than Neu cells. These were inhibited by the TGF-beta inhibitor-soluble TGF-beta type II receptor (TbetaRII:Fc), suggesting they were activated by autocrine TGF-beta. TGF-beta stimulated migration of Neu cells into surrounding matrix, while the soluble TGF-beta inhibitor abrogated motility and invasiveness of NT cells. These data suggest that (i) the antimitogenic and prometastatic effects of TGF-beta can exist simultaneously and (ii) Neu does not abrogate TGF-beta-mediated antiproliferative action but can synergize with TGF-beta in accelerating metastatic tumor progression.