The worldwide invasion history of a pest ambrosia beetle inferred using population genomics.

Xylosandrus crassiusculus, a fungus-farming wood borer native to Southeastern Asia, is the most rapidly spreading invasive ambrosia species worldwide. Previous studies focusing on its genetic structure suggested the existence of cryptic genetic variation in this species. Yet, these studies used different genetic markers, focused on different geographical areas and did not include Europe. Our first goal was to determine the worldwide genetic structure of this species based on both mitochondrial and genomic markers. Our second goal was to study X. crassiusculus' invasion history on a global level and identify the origins of the invasion in Europe. We used a COI and RAD sequencing design to characterize 188 and 206 specimens worldwide, building the most comprehensive genetic data set for any ambrosia beetle to date. The results were largely consistent between markers. Two differentiated genetic clusters were invasive, albeit in different regions of the world. The markers were inconsistent only for a few specimens found exclusively in Japan. Mainland USA could have acted as a source for further expansion to Canada and Argentina through stepping stone expansion and bridgehead events. We showed that Europe was only colonized by Cluster II through a complex invasion history including several arrivals from multiple origins in the native area, and possibly including bridgehead from the United States. Our results also suggested that Spain was colonized directly from Italy through intracontinental dispersion. It is unclear whether the mutually exclusive allopatric distribution of the two clusters is due to neutral effects or due to different ecological requirements.

Superinfection of five Wolbachia in the alnus ambrosia beetle, Xylosandrus germanus (Blandford) (Coleoptera: Curuculionidae).

Wolbachia bacteria are among the most common endosymbionts in insects. In Wolbachia research, the Wolbachia surface protein (wsp) gene has been used as a phylogenetic tool, but relationships inferred by single-locus analysis can be unreliable because of the extensive genome recombination among Wolbachia strains. Therefore, a multilocus sequence typing (MLST) method for Wolbachia, which relies upon a set of five conserved genes, is recommended. In this study, we examined whether the alnus ambrosia beetle, Xylosandrus germanus (Blandford), is infected with Wolbachia using wsp and MLST genes. Wolbachia was detected from all tested specimens of X. germanus (n=120) by wsp amplification. Five distinct sequences (i.e. five alleles) for wsp were found, and labeled as wXge1-5. MLST analysis and molecular phylogeny of concatenated sequences of MLST genes identified wXge3 and wXge5 as closely-related strains. The detection rate of wXge4 and wXge1 was 100% and 63.3%, respectively; wXge2, wXge3 and wXge5 were detected from less than 15% of specimens. We performed mitochondrial haplotype analyses that identified three genetic types of X. germanus, i.e. Clades A, B and C. Wsp alleles wXge1, wXge2 and wXge4 were detected in all clade A beetles; wXge2 allele was absent from Clades B and C. We concluded that (i) five wsp alleles were found from X. germanus, (ii) use of MLST genes, rather than the wsp gene, are more suited to construct Wolbachia phylogenies and (iii) wsp alleles wXge2 and wXge3/wXge5 would infect clade A and clade B/C of X. germanus, respectively.

[Pulsatile secretion of ovarian steroids in the mid-luteal phase of the menstrual cycle].

The possibility of the pulsatile secretion of pituitary gonadotropins (LH and FSH) and ovarian steroids (estradiol and progesterone) was studied. In addition, an evaluation was made of the regulatory factors for steroid secretion of corpus luteum in view of the response behavior of the secretion of LH, FSH, estradiol and progesterone when loaded with hCG and gonadotropin releasing hormone (Gn-RH). The study was performed on 9 cases of infertile women in the mid-luteal phase of a normal menstrual cycle. In 5 cases, blood was collected every 30 minutes and over 24 hours. Thereafter, 2,500 iu of hCG was given twice to another subject at 8 hour intervals, and blood was collected every 30 minutes from immediately after the 1st administration over 16 hours. In the other 3 cases, 15 micrograms of Gn-RH was given at an interval of 90 minutes, and blood was collected every 20 minutes for 16-24 hours. Then, the frequency and amplitude of each pulse for LH, FSH, estradiol and progesterone were calculated under the modified Santen's rule in situ and when loaded with Gn-RH, and the relationship between pulses of gonadotropins and those of estradiol and progesterone was analysed by determining the number of concomitant pulses. The hormone dynamics when loaded with hCG were also assessed. The pulse frequency and amplitude in situ of each hormone were 10.6 +/- 0.8 times/24 h and 4.9 +/- 0.6 miu/ml for LH, 9.9 +/- 9.9 times/24h and 1.3 +/- 0.1 miu/ml for FSH, 9.2 +/- 0.9 times/24h and 34.3 +/- 2.7 pg/ml for estradiol, 7.4 +/- 0.5 times/24 and 3.7 +/- 0.4 ng/ml for progesterone. The coincidence of estradiol pulses and LH pulses was 37 times, and the concomitant ratio of LH pulse to estradiol pulse was 81%. The coincidence of progesterone pulses and LH pulses was 31 times, and the concomitant ratio of LH pulse to progesterone pulse was 84%. Furthermore, the concomitant ratio of FSH pulse to estradiol pulse or progesterone pulse was 61% or 70%, respectively. The mean plasma concentration of LH, estradiol and progesterone during 8 hours after the 1st administration and 2nd administration of hCG changed from 29.9 +/- 2.3 to 41.8 +/- 1.6 miu/ml, from 140.3 +/- 3.0 to 160.6 +/- 3.6 pg/ml and from 19.2 +/- 1.0 to 25.7 +/- 0.6 ng/ml, respectively. These values increased significantly after the second injection (P less than 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)

[Monitoring of follicles by ultrasonography during induction with HMG-HCG treatment--especially on the prevention of side effects].

Estrogen levels are a useful indicator to use in predicting of ovarian hyperstimulation syndrome (OHSS) which is one of the side effects of HMG-HCG therapy. However, the quantitative assay of estrogens entails cumbersome time-consuming procedures. The present study represents our attempt to establish criteria for predicting the occurrence of OHSS by the use of ultrasonography (USG), a diagnostic procedure that can be performed quickly and conveniently. The subjects were 40 anovulatory women (79 cycles) receiving HMG-HCG therapy. Each patient had USG performed at the time of switching to HCG in a regimen of sequentially administered gonadotropins and was measured for maximum follicular diameter (FD) and total of vertical follicular area (FA) to correlate measurements of these parameters with simultaneously determined serum estradiol (E2) levels. A study was also made of relationships of FD and FA with ovulation and OHSS. The results are summarized as follows: No distinct correlation was observed between FD and E2 (r = 0.3794). It should be noted, however, that the therapy was successful in inducing ovulation in those cases in which the patient was switched to HCG from HMG when FD was 18mm or above. There was a significant correlation between FA and E2 (r = 0.8113, p less than 0.001). FA was thus proven to well reflect E2 levels and hence to be a parameter of the predictive value for OHSS. All but one (with moderate OHSS) of 26 cases showing evidence of OHSS had FA values of more than 6.0cm2, while those developing severe OHSS invariably.(ABSTRACT TRUNCATED AT 250 WORDS)