The karyotypes of 94 species of Indian ants were examined. Their chromosome numbers range almost continuously between n=5 and 38, though the frequency distribution is bimodal with a remarkable antimode at n=11 and two modal points at n=10 and 15. Based on this bimodal distribution, Indian ants were classified into two groups: Lower-numbered species (n<_11) and higher-numbered species (n>11), the former being characterized by metacentric-rich karyotypes, and acrocentrics predominate in the latter.The three major subfamilies (Ponerinae, Myrmicinae, and Formicinae) showed a highly divergent distribution in chromosome number, ranging between n= 7-38, 6-35, and 8-27, respectively, suggesting a convergence in karyotype evolution of each subfamily, Another three subfamilies, of which only a few species were examined, had moderate or lower numbers, i.e., n=5-14 in Dolichoderinae, n=14 in Cerapachyinae, and n=12 in Dorylinae. We found four Robertsonian polymorphisms, two pericentric inversion polymorphisms, and four reciprocal translocations, three of which were fixed. Robertsonian polymorphisms were found only in higher-numbered species, while translocations were restricted to lower-numbered species. A possible biological significance for this nonrandom distribution of rearrangements is discussed with reference to karyotype evolution in ants.

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n-3 Polyunsaturated fatty acids (PUFA) have a chemopreventive effect while n-6 PUFA promote carcinogenesis. The effect of these essential fatty acids may be related to oxidative stress. Therefore, the study was designed to evaluate the effect of different ratios of fish oil (FO) and corn oil (CO) in the prevention of colon cancer. Male Wistar rats were divided into control, dimethylhydrazine dihydrochloride (DMH) treated, FO + CO (1:1) and FO + CO (2.5:1). All the groups, except the control received a weekly injection of DMH for 4 weeks. The animals were sacrificed either 48 h later (initiation phase) or kept for 16 weeks (post initiation phase). DMH treatment in the initiation phase animals showed mild to moderate inflammation, decreased ROS and TrxR activity, increased antioxidants, apoptosis and ACF multiplicity. The post initiation study showed severe inflammation with hyperplasia, increased ACF multiplicity and ROS levels, a decrease in antioxidants and apoptosis. The FO + CO (1:1) treated animals showed severe inflammation, a decrease in ROS, an increase in antioxidants and apoptosis in the initiation phase. FO + CO (1:1) in the post initiation phase and FO + CO (2.5:1) in the initiation showed mild inflammation, increased ROS, apoptosis and decreased antioxidants. There was a decrease in ACF multiplicity and ROS levels, increased antioxidants and apoptosis in the post initiation phase study. The present study suggests that FO has a dose- and time-dependent chemopreventive effect in colon cancer mediated through oxidative stress and apoptosis.

The inside of a space-faring vehicle provides a set of conditions unlike anything experienced by bacteria on Earth. The low-shear, diffusion-limited microenvironment with accompanying high levels of ionizing radiation create high stress in bacterial cells, and results in many physiological adaptations. This review gives an overview of the effect spaceflight in general, and real or simulated microgravity in particular, has on primary and secondary metabolism. Some broad trends in primary metabolic responses can be identified. These include increases in carbohydrate metabolism, changes in carbon substrate utilization range, and changes in amino acid metabolism that reflect increased oxidative stress. However, another important trend is that there is no universal bacterial response to microgravity, as different bacteria often have contradictory responses to the same stress. This is exemplified in many of the observed secondary metabolite responses where secondary metabolites may have increased, decreased, or unchanged production in microgravity. Different secondary metabolites in the same organism can even show drastically different production responses. Microgravity can also impact the production profile and localization of secondary metabolites. The inconsistency of bacterial responses to real or simulated microgravity underscores the importance of further research in this area to better understand how microbes can impact the people and systems aboard spacecraft.

~T E S XCVIII-C AND THBEE TEXT-FIQWES SYNOPSISThe spermatogenesis of the honey-bee, Apia indiea (F.), has been worked out with special referenceThe haploid number of sixteen chromosomes in the parthenogenetic malea remains constant throughMeiosis I is abortive, resulting in the formation of a definite non-nucleated cytoplasmic bud containingThe significance of an extra-and an intra-nuclear spindle in relation to the abortive meiosisisdisouased. Meiosis I1 is normal 80 far aa the nuclear division is concerned. The cytoplaam, however, dividea unequally, resulting in the formation of a normal spermatid and a diminutive non-functional spermatidThe mitochondria are in the form of 6lamenta and granules in the early stagea. During meiosis I they assume a characteristic "blebbed" appearance. In the spermatid they fuse to form a typical mitochondrisl nebenkern, which ultimately givea rise to the mihhondrial sheath around the axial filament of the sperm.A number of typical duplex spheroids ("Golgi dictyosomes"), each with a lipid sheath enclosing a non-lipid medulla, are present in the epermatocytes. In the spermatid these duplex spheroids fuse to form a typical single acroblast which is sloughed off a%r depositing a pro-ecrosome at the nuclear membrane. The pro-acrosome condenses to form the acmsome of the ripe sperm.to the abortive meiosis and the role of cytoplasmic organellea. out spermatogenesis. some extra-nuclear spindle fibres and the cytoplasmic body. M Y . IKTRODUCTIONEXCEPT for the recent brief reviews, cytological information on Hymenoptera in general and the honey-bee in particular is scanty. Almost all the previous workers on the honeybee (viz.: Meves, 1904(viz.: Meves, , 1907Mark & Copeland, 1907; Doncaster, 1907; Nachtsheim, 1913 ; Sanderson & Hall, 1948 ; Hachinohe & Onishi, 1952 ; and others) have shown that the number of chromosomes in the drone remains sixteen in all the stages of meiosis. According to the recent work by Manning (1949Manning ( , 195oa-c, 1952, however, this is not so. Manning believes that in meiosis I1 one of the chromosomes is not included in the spermatid, with the result that sperms with only fifteen chromosomes are produced. But Sanderson and Hall (1951), Ruttner and Mackensen (1952), and Ken and Laidlaw (1956) do not agree with Manning.Similarly Walker (1949), and Smith and Peacock (1957) have challenged the views of previous workers regarding the clumping of the metaphase I chromosomes and the formation and nature of the cytoplasmic bud during the abortive meiosis I.