In-Process Error-Matching Measurement and Compensation Method for Complex Mating

This study proposed an error-matching measurement and compensation method for curve mating and complex mating. With use of polynomial curve fitting and least squares methods for error analysis, an algorithm for error identification and error compensation were proposed. Furthermore, based on the proposed method, an online error-matching compensation system with an autorevising function module for autogenerating an error-compensated NC program for machining was built. Experimental verification results showed that the proposed method can effectively improve the accuracy of assembly matching. In a curve-type mating experiment, the matching error without compensation was 0.116 mm, and it decreased to 0.048 mm after compensation. The assembly accuracy was improved by 28%. In a complex-type mating experiment, the verification results showed that the error reductions after compensation for three mating shapes (straight line, triangle, and curve shape) were 81%, 87%, and 79%, respectively. It showed that the proposed method can improve the assembly accuracy for complex mating shapes, which would also be improved without losing production efficiency.

Horizontal gene transfer of copper-containing membrane-bound monooxygenase (CuMMO) and di-iron soluble monooxygenase (SDIMO) in ethane- and propane-oxidizing Rhodococcus

The families of copper-containing membrane-bound monooxygenases (CuMMOs) and soluble di-iron monooxygenases (SDIMOs) are not only involved in methane oxidation but also in short-chain alkane oxidation. Herein, we describe Rhodococcus sp. ZPP, a bacterium able to grow with ethane or propane as the sole carbon and energy source and report on horizontal gene transfer (HGT) of actinobacterial hydrocarbon monooxygenases (HMO) of the CuMMO family and sMMO (soluble methane monooxygenase)-like SDIMO in the genus Rhodococcus. The key function of HMO in strain ZPP for propane oxidation was verified by allylthiourea inhibition. The HMO genes (designated hmoCAB) and those encoding sMMO-like SDIMO (designated smoXYB1C1Z) are located on a linear mega-plasmid (pRZP1) of strain ZPP. Comparative genomic analysis of similar plasmids indicated mobility of these plasmids within the genus Rhodococcus. The plasmid pRZP1 in strain ZPP could be conjugatively transferred to a recipient R. erythropolis in a mating experiment and showed similar ethane and propane consuming activities. Finally, our findings demonstrate that horizontal transfer of plasmid-based CuMMO and SDIMO genes confers the ability to use ethane and propane on the recipient. Importance CuMMOs and SDIMOs initiate the aerobic oxidation of alkanes in bacteria. Here, the supposition that horizontally transferred plasmid-based CuMMO and SDIMO genes confer on the recipient the similar ability to use ethane and propane was proposed and confirmed in Rhodococcus. This study is a living example of HGT of CuMMOs and SDIMOs and outlines the plasmid-borne properties responsible for gaseous alkane-degradation. Our results indicate that plasmids can support rapid evolution of enzyme-mediated biogeochemical processes.

Semen Modulates the Expression of NGF, ABHD2, VCAN, and CTEN in the Reproductive Tract of Female Rabbits

Semen changes the gene expression in endometrial and oviductal tissues modulating important processes for reproduction. We tested the hypothesis that mating and/or sperm-free seminal plasma deposition in the reproductive tract affect the expression of genes associated with sperm-lining epithelium interactions, ovulation, and pre-implantation effects (nerve growth factor, NGF; α/β hydrolase domain-containing protein 2, ABHD2; C-terminal tensin-like protein, CTEN or TNS4; and versican, VCAN) in the period 10–72 h post-mating. In Experiment 1, does (n = 9) were treated with gonadotropin-releasing hormone (GnRH) (control), GnRH-stimulated, and vaginally infused with sperm-free seminal plasma (SP-AI), or GnRH-stimulated and naturally mated (NM). In Experiment 2, does (n = 15) were GnRH-stimulated and naturally mated. Samples were retrieved from the internal reproductive tracts (cervix-to-infundibulum) 20 h post-treatment (Experiment 1) or sequentially collected at 10, 24, 36, 68, or 72 h post-mating (Experiment 2, 3 does/period). All samples were processed for gene expression analysis by quantitative PCR. Data showed an upregulation of endometrial CTEN and NGF by NM, but not by SP-AI. The findings suggest that the NGF gene affects the reproductive tract of the doe during ovulation and beyond, influencing the maternal environment during early embryonic development.

Draft Genome Sequences of a Ceftazidime-Resistant Acinetobacter baumannii Donor and a Conjugal Escherichia coli Recipient with Acquired Resistance

A ceftazidime-resistant Acinetobacter baumannii strain was isolated from hospital wastewater and used as the donor in a filter mating experiment with an Escherichia coli strain as the recipient. Recipient, donor, and transconjugant were sequenced, and both donor and transconjugant were found to harbor highly similar plasmid sequences, suggesting that plasmid transfer had occurred.

Brainless but not clueless: earthworms boost their ejaculates when they detect fecund non-virgin partners

In many animals in which females store sperm, males may detect female mating status and, in order to outcompete rival sperm, increase ejaculate size when copulating with non-virgin females. Although most studies have been restricted to organisms with separate sexes, theoretical models suggest that sperm competition should also be an important selective agent shaping life-history traits in simultaneous hermaphrodites. Nevertheless, the empirical support for ejaculate adjustment in a mating opportunity is scarce in hermaphrodites. In the present study, we performed a double-mating experiment to determine whether earthworms ( Eisenia andrei ) detect the mating status of their partners and whether they respond by adjusting their ejaculate. We found that earthworms triplicated the donated sperm when mating with a non-virgin mate. Moreover, such increases were greater when the worms were mated with larger (more fecund) partners, indicating that earthworms perform a fine-tune control of ejaculate volume. The results of the present study suggest that, under high intensity of sperm competition, partner evaluation is subject to intense selection in hermaphrodite animals, and donors are selective about to whom they donate how much sperm.

Anti-Aging Effects of Nanpao®, a Kampo Medicine, on Reproductive Functions in Female Rats

The improvement effect of Nanpao, a Kampo medicine, on the age-related decline in reproductive function was evaluated in female rats given the test drug for a long-term period. Young rats were allocated to the cesarean section and natural delivery groups to examine reproductive performance (young rat groups). Five-month-old rats were allocated to the 3 groups (aged rat groups): 1 — control and 2 — Nanpao-treated groups. They were given orally in a dose of 0, 30 or 100mg/kg/day of the test drug, respectively. In aged rats, the first mating experiment was initiated at week 21 of dosing to evaluate reproductive performance by natural delivery and the second mating experiment at week 31 of dosing was evaluated by cesarean section. In the first and second mating experiments, various reproductive functions decreased in aged rats as compared to the young rats. On the other hand, loss of regular estrous cycles, decreases in delivery and pregnancy rates and mean fetal weights were inhibited in the treated groups as compared to the control group. In addition, decreases in the numbers of mean live offspring and fetuses were inhibited in the 100mg/kg/day group. In conclusion, Nanpao maintained normal embryo-foetal development in female rats.

Control of ovarian follicular growth and maturation by the corpus luteum and the placenta during pregnancy in sheep

Ovarian follicular growth and maturation and its control throughout pregnancy have not been described fully in sheep. Experiment 1 characterized the size and maturation (steroid production in vitro and aromatase activity) of ovarian follicles obtained at days 20, 50, 80 and 110 of pregnancy compared with those obtained at day 12 of the oestrous cycle. There was no difference in the number of small follicles (< 3 mm in diameter) between cyclic and pregnant ewes, regardless of the stage of pregnancy. There was a marked reduction (P < 0.01) in the number of medium follicles (3-5 mm) starting at day 80 of pregnancy. Large follicles (> 5 mm) were not detected at day 110 of pregnancy. In vitro testosterone output by follicles was constant throughout pregnancy. Oestradiol output remained steady until day 80, but decreased markedly at day 110 of pregnancy. This decrease was associated with a reduction in aromatase activity in follicles obtained at this stage. Experiment 2 examined the effect of administration of high concentrations of progesterone between day 100 and day 120 after mating on resumption of follicular growth in ewes that underwent Caesarean section at day 99 of pregnancy. In ewes that underwent Caesarean section, progesterone supplementation was successful in mimicking the profile found in pregnant ewes, but did not prevent re-initiation of follicular growth, as demonstrated by the presence of large follicles (> 5 mm) at day 120 after mating. Experiment 3 examined the effects of PGF(2alpha)-induced regression of the corpus luteum of day 100 of pregnancy on resumption of follicular growth. High concentrations of PGF(2alpha) (0.28 mg kg(-1) body weight) administrated at day 100 of pregnancy were required to initiate regression of the corpus luteum. At day 120 after mating, the mean (+/- SEM) diameter of the largest follicle in PGF(2alpha)-treated ewes (3.40 +/- 0.47 mm) was significantly greater (P < 0.05) than that in control pregnant ewes (2.52 +/- 0.34 mm). Experiment 4 examined the effect of removal of the fetus and of the corpus luteum at day 100 of pregnancy on resumption of ovulation. Removal of the corpus luteum by PGF(2alpha) treatment at the time of removal of the fetus resulted in earlier occurrence of short luteal phases (27.8 versus 40.6 days, PGF(2alpha)-treated versus non-treated) but did not alter the timing of the first normal luteal phases (41 days). In conclusion, the results from these experiments indicate that placental compounds play a major role in inhibiting follicular growth and maturation during late pregnancy in sheep.

Mating Awassi rams to Merino ewes causes an initial level of fibre contamination which decreases to an insignificant level eight weeks post-mating

The fleeces of Merino ewes mated by Awassi rams were analysed for the presence of contaminant fibres (pigmented, urine-stained and kemp). In a controlled shed mating, high numbers of contaminant fibres were found in the fleeces of the ewes, with the number of fibres transferred being proportional to the number of times the ram mounted the ewe. The number of fibres transferred during the shed mating were substantially higher than those found after paddock mating. In the latter instance, environmental conditions and contact with other sheep would have contributed to the loss of fibres from the recipients’fleeces. Each ram breed used in the paddock mating experiment, Merino, Awassi and Suffolk, transferred fibres into the fleeces of the mated ewes. The Suffolk transferred relatively more fibres than both the Awassi or the Merino rams, in addition the fibres from the Suffolk were significantly darker than those from the other breeds thus compounding the severity of the contamination. Both mating experiments demonstrated that the number of contaminant fibres remaining in the ewe’s fleece 8 weeks after mating was not different to that existing in the fleece of the ewes before mating. Therefore, in commercial flocks, the risk of contamination can be minimised by shearing breeding ewes 8 weeks after rams have been removed from the breeding flocks.

VARIATION OF SPERM PRECEDENCE IN THE ROVE BEETLE ALEOCHARA CURTULA (COLEOPTERA: STAPHYLINIDAE)

In order to quantify the outcome of sperm competition in the mating system of the rove beetle Aleochara curtula we performed three different mating experiment series. Paternity was established by DNA fingerprinting with oligonucleotide probes. We found a precedence of the last male with a proportion of eggs fathered by the last male of 87% (median). Nevertheless, we observed a large variation of P2-values in A. curtula and cases of mixed paternity were documented as well as cases of 100% or 0% paternity of the last male. The variation of P2-values correlates with the efficiency of spermatophore and sperm transfer.

Interspecific Hybridization of Meiotic Parthenogenetic Meloidogyne chitwoodi and M. fallax

Hybridization between two meiotic parthenogenetic species of root-knot nematodes, Meloidogyne chitwoodi and M. fallax, was investigated in two different crossing experiments on tomato plants grown in sand. The first experiment was a controlled cross between the two species. The second experiment was a bulk mating in a 1:1 mixture of two isolates. The haploid chromosome number of the parental isolates was n = 18. Successful interspecific hybridization was obtained, and the resulting hybrids produced egg masses. In eggs, cell division was observed, but most of them were without clear differentiation and consequently were sterile. Hatched F2 juveniles were small in number, not viable, and showed morphological distortions. In the progeny of the isolate mixture of the bulk mating experiment, parental-type females of the two isolates were present in equal numbers, and 10% of all females were nonviable hybrids. Similar ratios of parental-type and hybrid females were detected in roots of test plants grown in soil from a field sample that contained a mixture of M. chitwoodi and M. fallax populations. In the controlled cross experiment, isozyme electrophoresis of malate dehydrogenase was applied to distinguish the two species and their hybrids. In the bulk mating experiment, malate dehydrogenase, esterase, and glucose 6-phosphate dehydrogenase were used as markers, two by two simultaneously on the same individual females, providing conclusive evidence for the occurrence of hybrids. This is the first report on interspecific hybridization in Meloidogyne. The possible role of interspecific hybridization in species differentiation and interspecific exchange of genetic material within Meloidogyne is discussed.