The pattern of ovarian development in the prepubertal antarctic minke whale (Balaenoptera bonaerensis)

This study describes the morphological and morphometrical changes associated with prepubertal ovarian development in the Antarctic minke whale (Balaenoptera bonaerensis). Ovaries were harvested from 94 immature minke whales caught in the Antarctic Ocean during the summer feeding season (December-March). Notable differences in ovarian size and morphology were found among animals. Up to 10 folds difference in ovarian weight was found among prepubertal whales of similar body size. During the prepubertal period, ovaries grew slowly and approximately doubled their weight. The morphologies of right and left ovaries were almost identical while the growth of the ovary appears to occur preferentially on the right side. The most striking morphological feature was numerous small antral follicles less than 5 mm in diameter found in ovaries of younger immature whales. The occurrence of these ovaries was highest in whales less than 6 m long and gradually decreased as body length increased. In larger whales, the occurrence of ovaries with a smaller number of follicles up to 10 mm and thick tunica albuginea increased. Thus, the ovary of the Antarctic minke whale experiences bursts of small follicular development during the early prepubertal period before becoming a more developed ovary with fewer but larger follicles, and thick tunica albuginea.     

Risk factors for Campylobacter colonization in broiler flocks in Japan

The present study was conducted to estimate the prevalence of and to identify the risk factors for Campylobacter colonization in broiler flocks in Japan. Campylobacter colonization status in flock was evaluated by culturing pooled caecal excrement from 124 broiler flocks. Potential exposure to risk factors was evaluated with a questionnaire for the broiler producers. Odds ratios (ORs) were calculated using a multivariable logistic regression analysis. The prevalence of Campylobacter-positive flocks was 43.5% (upper and lower limits of 95% confidence interval (CI(95%) ): 34.8, 52.3). Multivariable logistic regression model identified two variables as risk factors for Campylobacter colonization. The ORs of Campylobacter colonization were higher in flocks in western Japan (OR=2.68; CI(95%) : 1.04, 6.91) than in eastern Japan, and in flocks supplied with undisinfected drinking water (OR=7.41; CI(95%) : 3.11, 17.66) than in those supplied with disinfected drinking water. These findings indicate that water may play an important role in Campylobacter colonization in broiler flocks in Japan and the use of disinfected water may reduce the risk of Campylobacter colonization.     

Parentage analysis of tea cultivars in Japan based on simple sequence repeat markers

Tea cultivars have been bred by individual selection of landraces and by crossbreeding, but the validation of the parentage is limited. In this study, we performed parentage analysis of 79 tea cultivars in Japan based on SSR markers to confirm or identify the parent-offspring relationships among them. The effectiveness of nine SSR markers for parentage analysis was validated by comparing them to the existing cleaved amplified polymorphic sequence markers. The former markers were detectable more alleles than the latter. Simulation of parentage analysis of the tea cultivars predicted biparental origins for 12 cultivars (‘Houshun’, ‘Mie ryokuhou no. 1’, ‘Surugawase’, ‘Tenmyo’, ‘Yamanoibuki’, ‘Harumidori’, ‘Koushun’, ‘Minekaori’, ‘Okumusashi’, ‘Saemidori’, ‘Sofu’, and ‘Toyoka’), in the first five of which candidate parents of yet-to-be-defined pedigree were newly identified. Comparisons of a total of 41 SSR genotypes confirmed the newly-identified parentages of ‘Asahi’ for ‘Tenmyo’, ‘Rokurou’ for ‘Houshun’, ‘Surugawase’, and ‘Yamanoibuki’, and ‘Yamatomidori’ for ‘Mie ryokuhou no. 1’. The maternity of seven cultivars out of the 12 was also confirmed with chloroplast DNA sequences. Uniparental origins were confirmed for 25 cultivars. This parentage analysis has improved our knowledge of tea pedigrees and will aid in the development of new cultivars.     

Development of two new molecular markers specific to cytoplasmic male sterility in tuber mustard (<Emphasis Type="Italic">Brassica juncea</Emphasis> var. <Emphasis Type="Italic">tumida</Emphasis> Tsen et Lee)

A novel and stable cytoplasmic male sterility CMS line of tuber mustard has been bred by subsequent backcrosses for 10 years. Two specific markers atpA and orf220 were cloned and partially characterized in our previous study (Zhang et al. 2003). In this study, two new molecular markers, orf256 and orf305/orf324, have been isolated and identified. The orf256 gene size was found to be 825 bp in CMS line and a 1,357 bp in its maintainer line. Sequence analysis indicated that the orf256 gene was an entire coding sequence and downstream of the cox1 gene. Interestingly, the 906 bp fragment, which contains part of the sequence of orf222, nad5 and orf139 genes, was found to be inserted from the 451st bp of 5′-flank of the 1,357 bp fragment. In the same way, the orf324 gene was isolated from CMS line and orf305 gene from its maintainer line. Both of them are entire coding sequences, upstream from nad3 and rps12 gene, and co-transcribed with the nad3 and rps12 genes. In addition, two molecular markers, orf256 and orf324/orf305, have been successfully converted into the SCAR markers. Subsequently, ORF256, ORF324, ORF305 protein and ORF256-M-431 fragment are predicated to contain signal peptide sequences, and ORF220 was predicated to contain signal anchor sequence. RFLP analysis results revealed that all of the molecular markers exhibited polymorphisms. Northern blot analysis indicated that the expression level of these genes in CMS line is higher than that of the maintainer line. In the mass, all of these genes are expressed lower in the leaf than that of floral organs between the CMS line and its maintainer line. The difference in expression pattern of different mitochondrial specific marker genes suggests that the abundance of mitochondrial proteins is differentially regulated in the organ/tissue development in tuber mustard. Results of this study also provide some novel and useful clues to explore the biological function of these specific marker genes in the tuber mustard.     

An SSR-based genetic map of pepper (Capsicum annuum L.) serves as an anchor for the alignment of major pepper maps

Of the Capsicum peppers (Capsicum spp.), cultivated C. annuum is the most commercially important, but has lacked an intraspecific linkage map based on sequence-specific PCR markers in accord with haploid chromosome numbers. We constructed a linkage map of pepper using a doubled haploid (DH) population derived from a cross between two C. annuum genotypes, a bell-type cultivar ‘California Wonder’ and a Malaysian small-fruited cultivar ‘LS2341 ({"type":"entrez-nucleotide","attrs":{"text":"JP187992","term_id":"347495878"}}JP187992)’, which is used as a source of resistance to bacterial wilt (Ralstonia solanacearum). A set of 253 markers (151 SSRs, 90 AFLPs, 10 CAPSs and 2 sequence-tagged sites) was on the map which we constructed, spanning 1,336 cM. This is the first SSR-based map to consist of 12 linkage groups, corresponding to the haploid chromosome number in an intraspecific cross of C. annuum. As this map has a lot of PCR-based anchor markers, it is easy to compare it to other pepper genetic maps. Therefore, this map and the newly developed markers will be useful for cultivated C. annuum breeding.     

Screening method for determination of high levels of cadmium, lead, and copper in foods by polarized Zeeman atomic absorption spectrometry using discrete nebulization technique

A screening method for determination of cadmium, lead, and copper in foods was developed. The sample (1-3 g) is digested with HNO3-H2SO4-HClO4 in a centrifuge tube attached to a straight glass tube that prevents loss of HNO3 by volatilization. After digestion, potassium iodide, H2SO4, and MIBK (4-methyl 2-pentanone) are added, and the metals are extracted with MIBK as metal iodides. The MIBK solution is injected and the metals are determined by flame polarized Zeeman atomic absorption spectrometry using a discrete nebulization technique. Recoveries of metals from fortified milk powder, unpolished rice, fish, beef, peanut butter, apple, and cabbage were satisfactory. The analytical results for NBS Oyster Tissue and NIES Pepperbush, Chlorella, and Mussel agreed with certified or reference values except lead in Pepperbush. The limits of quantitation for cadmium, lead, and copper were 0.01, 0.09, and 0.02 ppm, respectively. This method is simple and safe for routine analysis of high levels of cadmium, lead, and copper in foods.     

Vegetative and floral characteristics of interspecific Brassica chimeras produced by in vitro grafting

Summary Interspecific Brassica chimeras (Brassica campestris+B. oleracea) were synthesized according to an in vitro graftculture method, and propagated by tissue culture of axillary buds or chimeric explants. A total of 127 regenerants obtained were investigated. The mericlinal chimera type was more easily produced than the other periclinal and revertant types. No sectorial chimera was produced. The flowering habit and inflorescence type of the chimeras were found to be controlled by the constitution of three tissue layers, but the petal shape and color were controlled only by the two outer tissue layers. Pollen viability of the chimeras were generally lower and more variable in parts than those of the parental types.     

Water transfer from agriculture to urban domestic users: a case study of the Tone River Basin, Japan

Agricultural water reorganization measures (AWRM) is an approach that has been adopted in Japan for more than 30 years to capture excess water from agriculture for other uses by relying on the modernization of existing irrigation infrastructures. This paper reviews the history and processes of four such permanent water transfers by AWRM in the Tone River Basin, specifically those conducted in the Saitama Prefecture, Japan. The benefit of AWRM for the agricultural sector is the lowering of rehabilitation costs by sharing part of it with the city sector. AWRM does not require saving water at the on-farm level. Instead, the labor requirement of farmers is reduced by the rehabilitation and installation of pipelines. The benefit to the city is the lower cost, when compared with costs for the development of new water resources, and the relatively short duration of the project, which are important factors in an environment of the rapid increase in domestic water demand.