Evolutionary divergence times in the Annonaceae: evidence of a late Miocene origin of Pseuduvaria in Sundaland with subsequent diversification in New Guinea

Background  

Phylogenetic analyses of the Annonaceae consistently identify four clades: a basal clade consisting of Anaxagorea, and a small 'ambavioid' clade that is sister to two main clades, the 'long branch clade' (LBC) and 'short branch clade' (SBC). Divergence times in the family have previously been estimated using non-parametric rate smoothing (NPRS) and penalized likelihood (PL). Here we use an uncorrelated lognormal (UCLD) relaxed molecular clock in BEAST to estimate diversification times of the main clades within the family with a focus on the Asian genus Pseuduvaria within the SBC. Two fossil calibration points are applied, including the first use of the recently discovered Annonaceae fossil Futabanthus. The taxonomy and morphology of Pseuduvaria have been well documented, although no previous dating or biogeographical studies have been undertaken. Ancestral areas at internal nodes within Pseuduvaria are determined using dispersal-vicariance analysis (DIVA) and weighted ancestral area analysis (WAAA).     

Territorial defense against various food competitors in the Tanganyikan benthophagous cichlid <Emphasis Type="Italic">Neolamprologus tetracanthus</Emphasis>

Territorial defense of nonbreeding female Neolamprologus tetracanthus, a shrimp-eating Tanganyikan cichlid, was investigated. Females defended territories (=home ranges, ca. 1m across) against a variety of intruding fishes. Conspecific females were usually attacked outside the territories, heterospecific benthivores (shrimp eaters) and omnivores near the border of the territories, and piscivores, algae and detritus feeders, and herbivores inside the territories. Females used some parts of the sandy substrate in the territories for foraging (foraging areas). Territorial defense prevented most of the conspecific females and benthivores from intruding into the foraging areas. In omnivores, piscivores, and algae and detritus feeders, about half the intruders were repelled from the foraging areas, although herbivores were infrequently repelled in the areas. Soon after removal of the resident females, many food competitors invaded the foraging areas and eagerly devoured prey, suggesting that the territories are maintained for food resource protection from these competitors. Females are likely to discriminate intruding fishes and change their territorial defense primarily on the basis of the degree of dietary overlap, resulting in monofunctional serial territories.     

Effects of diet on female fecundity and larval development in the carrion beetle Necrophila japonica

The carrion beetle subfamily Silphinae (Coleoptera: Silphidae) contains dominant macroinvertebrates of soil ecosystems in temperate zones. However, their feeding habits, which determine the role of each species in the ecosystem, have not been sufficiently studied. Moreover, although a diet shift from necrophagy on vertebrate carcasses to predatory feeding on invertebrates is known to occur in this subfamily, the processes and mechanisms of this shift have also been inadequately addressed. We examined female fecundity and larval development on various diets in a Silphinae species, Necrophila (Eusilpha) japonica (Motschulsky). The experimental diets included a meat diet and various invertebrate diets, which reflect the ‘ancestral’ feeding habit in Silphinae, necrophagy, and the ‘derivative’ feeding habit, predatory feeding. Female fecundity was significantly higher on the meat diet (minced beef) than on an insect larvae diet (mealworms and dipteran larvae) but did not significantly differ from that on an earthworm diet. Larval developmental performance was significantly higher on the earthworm diet than on the meat and insect larvae diets. Our results for larval development were consistent with those of previous stable isotope analyses of the same species, in which isotopic values of larval samples agree with those of hypothetical consumers that utilize earthworms. The consistency of results among different methods indicates that N. japonica larvae are most likely earthworm feeders. In contrast, our results for the female fecundity experiment differed from those of previous stable isotope analyses, in which vertebrate carcasses unlikely serve as the staple diet of adults in the field; thus, the feeding habits of N. japonica adults remain unresolved. Our observations that females and larvae performed best on the meat and earthworm diets, respectively, may indicate that, in Silphinae, the diet shift from necrophagy to predatory habits occurs earlier in larvae than in adults.     

The MSG1 and AXR1 genes of Arabidopsis are likely to act independently in growth-curvature responses of hypocotyls

Growth-curvature responses of hypocotyls of Arabidopsis thaliana (L.) Heynh. were measured in double mutants between msg1 and axr1, both of which are auxin-resistant and defective in hypocotyl growth curvature induced upon unilateral application of auxin. The msg1 axr1 double mutants showed no auxin-induced growth curvature, that is, they exhibited the msg1 phenotype, though the axr1 defects were partial. Hypocotyls of both the msg1 and axr1 mutants were partially defective in second-positive phototropism, whereas the double mutants lost the response completely. When grown on vertically held agar plates, the axr1 mutant showed normal hypocotyl gravitropism and the mutation did not affect the reduced hypocotyl gravitropism of msg1. Hypocotyls of msg1 and axr1 mutants grew upward like wild-type ones when grown along an agar surface, while they grew more randomly when grown without an agar support, suggesting that axr1 hypocotyls are not completely normal in gravitropism. The extent of defects in growth orientation increased in the order: msg1 axr1 double mutants > msg1 > axr1 > wild type. The hypocotyls of these mutants showed auxin resistance in the order: msg1 axr1 > axr1 > msg1 > wild type. The msg1 mutant had epinastic leaves and axr1 had wrinkled leaves; leaves of the msg1 axr1 double mutants were epinastic and wrinkled. These results suggest that MSG1 and AXR1 act independently in separate pathways of the reactions tested in the present study. In contrast, the phenotype of the msg1 aux1 double mutants shows that AUX1 is not significantly involved in these phenomena. Received: 12 July 1998 / Accepted: 16 August 1998     

MicroRNAs associated with metastatic prostate cancer

Objective

Metastasis is the most common cause of death of prostate cancer patients. Identification of specific metastasis biomarkers and novel therapeutic targets is considered essential for improved prognosis and management of the disease. MicroRNAs (miRNAs) form a class of non-coding small RNA molecules considered to be key regulators of gene expression. Their dysregulation has been shown to play a role in cancer onset, progression and metastasis, and miRNAs represent a promising new class of cancer biomarkers. The objective of this study was to identify down- and up-regulated miRNAs in prostate cancer that could provide potential biomarkers and/or therapeutic targets for prostate cancer metastasis.

Methods

Next generation sequencing technology was applied to identify differentially expressed miRNAs in a transplantable metastatic versus a non-metastatic prostate cancer xenograft line, both derived from one patient''s primary cancer. The xenografts were developed via subrenal capsule grafting of cancer tissue into NOD/SCID mice, a methodology that tends to preserve properties of the original cancers (e.g., tumor heterogeneity, genetic profiles).

Results

Differentially expressed known miRNAs, isomiRs and 36 novel miRNAs were identified. A number of these miRNAs (21/104) have previously been reported to show similar down- or up-regulation in prostate cancers relative to normal prostate tissue, and some of them (e.g., miR-16, miR-34a, miR-126*, miR-145, miR-205) have been linked to prostate cancer metastasis, supporting the validity of the analytical approach.

Conclusions

The use of metastatic and non-metastatic prostate cancer subrenal capsule xenografts derived from one patient''s cancer makes it likely that the differentially expressed miRNAs identified in this study include potential biomarkers and/or therapeutic targets for human prostate cancer metastasis.     

Nucleotide sequence of cDNA and primary structure for hard tail growth hormone

Full-length cDNA for hard tail growth hormone (htGH) has been cloned, and the nucleotide and deduced amino acid sequences have been analyzed. htGH is composed of 188 amino acid residues, and it shows 79, 74, 72, 59, 56, 37, 33 and 30% identity of amino acid with yellow tail, tuna, sea bream, flounder, salmon, blue shark, bullfrog and human GHs, respectively.     

The massugu1 mutation of Arabidopsis identified with failure of auxin-induced growth curvature of hypocotyl confers auxin insensitivity to hypocotyl and leaf.

Unilateral application of indole-3-acetic acid (IAA) in a lanolin base to hypocotyls of partially etiolated seedlings of wild-type Arabidopsis thaliana induced growth curvature in a dose-dependent manner. The effects of IAA in concentrations from 1 to 1000 microM were studied, with maximum IAA-induced curvature at 100 microM. Three IAA-insensitive mutants were isolated and are all in the same locus, massugu1 (msg1). They did not undergo hypocotyl growth curvature at any of the IAA concentrations tested. msg1 is recessive and is located on chromosome 5. msg 1 hypocotyl growth is resistant to 2,4-dichlorophenoxyacetic acid (2,4-D), but the roots are as sensitive to 2,4-D as the wild type. Growth of the hypocotyl was inhibited to essentially the same extent as the wild type by 6-benzylaminopurine, abscisic acid, and 1-aminocyclopropane-1-carboxylate, an ethylene precursor. The msg1 leaves were also resistant to 2,4-D-induced chlorosis. The gravitropic response of the msg1 hypocotyl takes much more time to initiate and achieve the wild-type degree of curvature, whereas the msg1 roots responded normally to gravity. The mature plants and the etiolated seedlings of msg1 were generally wild type in appearance, except that their rosette leaves were either epinastic or hyponastic. msg1 is the first auxin-insensitive mutant in which it effects are mostly restricted to the hypocotyl and leaf, and msg1 also appears to be auxin specific.