Characterization of Mendelian and Non-Mendelian Mutant Strains by Micronuclear Transplantation in Paramecium tetraurelia

ABSTRACT. Mutant strain d48 and d12 cannot express serotype A. In d48, the A i-antigen gene is present in the micronucleus, but not in the macronucleus. It has recently been shown that d12 contains the A gene in its micronucleus, but its macronucleus lacks the gene. Micronuclear transplantations into enucleated cells were performed to analyze those mutants. Reciprocal transplantation between wild type and d48 confirmed that d48 contains the A gene in the micronucleus and its cytoplasm is defective. Wild type 51 enucleated cells into which were transplanted d12 micronuclei could not express A. Amiccronucleate d12 cells into which were transplanted normal micronuclei from 51 or d48 showed no expression of A. These results show that even if the micronucleus of d12 contains the A gene, it must be abnormal, and its cytoplasm is also defective the same as d48. Genetic analysis showed that heterozygote of d12 and wild type 51 or d48 caused a cure of the cytoplasmic defect of d48 and d12 during the development of macronuclei.     

A review of the distribution of all species of deer (Tragulidae, Moschidae and Cervidae) in China

Twenty-one species of deer occur in China: one species of Tragulidae, three species of Moschidae and 17 species of Cervidae. The foundation of this review is the research conducted in the early 1940s by Allen, combined with the research and investigation by the authors and other Chinese specialists since that time. This paper focuses on the tentative distribution of these species of deer for future research efforts.     

The effect of chlorophyll content on changes of photochemical reactions in intact kidney bean leaves

Abstract. Activation spectra of photochemical reactions were measured by a flash spectrophotometer in leaves having varying chlorophyll contents at different stages of greening. The increase of chlorophyll concentration up to 30 nmol cm^-2 elevated the rates of photochemical reactions at all wavelengths of light used, and was found to be produced by an increase in the amounts of reaction centres. Further accumulation of chlorophyll up to 40 nmol cm^-2 was associated with an increase in light-harvesting chlorophyll, an improved rate of photochemical reactions around 600 nm and at 700 nm, and self-absorption and screening effects where chlorophyll absorbed maximally (400–450 nm and around 680 nm).     

'METACHRONOUS' CLEAVAGE AND INITIATION OF GASTRULATION IN AMPHIBIAN EMBRYOS

The cleavage pattern in the egg of Xenopus laevis has been investigated with the aid of time-lapse cinematography. From the 5th cleavage onward, divisions of the surface blastomeres are not synchronous but metachronous. A few blastomeres in a very restricted region which is situated in most cases in the dorsal side of the animal hemisphere, slightly distant from the median line and near the equatorial junction of the animal and vegetal hemispheres, divide before the other blastomeres, and a wave-like propagation of the divisions travels along the surface from that region toward the animal and vegetal poles. The wave-like propagation ends in the vegetal pole region. In the animal hemisphere, this pattern of cleavage is continued until the 13th cleavage and thereafter the divisions of surface blastomeres become asynchronous. In the vegetal pole region, however, the 14th metachronous division of blastomeres is clearly observed in the film. Gastrulation begins after 14 cleavages.     

Fourteen polymorphic microsatellite loci in the field gudgeon,Gnathopogon elongatus elongatus

We isolated and characterized 14 polymorphic microsatellite loci for the field gudgeon, Gnathopogon elongatus elongatus, a popular freshwater species in streams including agricultural canals in Japan. The number of observed alleles for each locus ranged from 9 to 24, and the values of observed and expected heterozygosities ranged from 0.750 to 1.000 and from 0.832 to 0.953, respectively. These microsatellite markers will be useful for studies of population genetic structure and genetic variability of the field gudgeon.     

Isolation and characterization of polymorphic microsatellite DNA markers in the Japanese eight‐barbel loach,Lefua echigonia

We isolated and characterized 17 polymorphic microsatellite loci for the Japanese eight‐barbel loach, Lefua echigonia, an endangered freshwater species in streams including agricultural canals in Japan. The number of observed alleles for each locus ranged from two to nine, and the values of observed and expected heterozygosities ranged from 0.125 to 0.844 and from 0.148 to 0.876, respectively. All loci conformed to Hardy–Weinberg equilibrium. Genetic linkage disequilibrium analysis between all pairs of the loci showed no significant departure from the null hypothesis between any of the loci.     

A redescription of Cythere japonica Hanai, 1959 (Podocopida: Ostracoda)

Cythere japonica was proposed by Hanai (1959) as a new species of the genus Cythere , from the Pleistocene Sawane Formation in Sado Island, Niigata Prefecture, Japan. The characters of carapace were already known, but the appendages have not been previously described. The authors formerly considered that this species should be separate from the genus Cythere sensu stricto because it has twice as many sieve-type pore systems as typical Cythere species, and a markedly higher carapace. The existence of living Cythere japonica in the tidal zone of north-west Japan is confirmed, and its taxonomic position re-examined on the basis of its appendages and the ontogeny of pore systems. The appendages, except for the copulatory organ, are almost identical with those of other Cythere species, and their pore systems share the same pattern in and before the A-4 moult stage. On the basis of these features this species should be retained in the genus Cythere. Phylogenetic relationships are considered on the basis of the ontogeny of pore systems.
The abdominal segments of podocopid Ostracoda, which have always been regarded as difficult to observe because of their fusion, are shown clearly by the SEM.     

Life‐history traits related to diapause in univoltine and bivoltine populations of Ypthima multistriata (Lepidoptera: Satyridae) inhabiting similar latitudes

In most temperate insects, diapause strategies and voltinism generally exhibit latitudinal clines, supporting the concept that they represent adaptations to climate. In contrast, in the satyrine butterfly Ypthima multistriata Butler, local populations with different voltinism patterns are geographically intermingled, suggesting that life‐history traits related to diapause may differ even between geographically and phylogenetically close populations. In this study, we experimentally examined the critical photoperiod for diapause induction and the larval developmental period in two univoltine and two bivoltine populations of Y. multistriata, all of which inhabit virtually the same latitude (34.652–34.750°N). We found that the critical photoperiod for diapause induction was longer in the univoltine populations than in the bivoltine populations. Moreover, the larval period under the long day length treatment was different among populations in both sexes, although significant differences were also detected between populations with the same voltinism. These results indicate that in Y. multistriata, life‐history traits related to diapause can not be attributed merely to climatic conditions such as temperature or day length, which depend largely on latitude. Therefore, we suggest that biotic elements, such as leaf toughness, as well as abiotic elements should be taken into account in attempts to explain the enigmatic pattern of geographic variation in the diapause strategies of Y. multistriata.