Genomes, expression profiles, and diversity of mitochondria of the White-footed Deermouse Peromyscus leucopus, reservoir of Lyme disease and other zoonoses

The cricetine rodents Peromyscus leucopus and P. maniculatus are key reservoirs for several zoonotic diseases in North America. We determined the complete circular mitochondrial genome sequences of representatives of 3 different stock colonies of P. leucopus, one stock colony of P. maniculatus and two wild populations of P. leucopus. The genomes were syntenic with that of the murids Mus musculus and Rattus norvegicus. Phylogenetic analysis confirmed that these two Peromyscus species are sister taxa in a clade with P. polionotus and also uncovered a distinction between P. leucopus populations in the eastern and the central United States. In one P. leucopus lineage four extended regions of mitochondrial pseudogenes were identified in the nuclear genome. RNA-seq analysis revealed transcription of the entire genome and differences from controls in the expression profiles of mitochondrial genes in the blood, but not in liver or brain, of animals infected with the zoonotic pathogen Borrelia hermsii. PCR and sequencing of the D-loop of the mitochondrion identified 32 different haplotypes among 118 wild P. leucopus at a Connecticut field site. These findings help to further establish P. leucopus as a model organism for studies of emerging infectious diseases, ecology, and in other disciplines.

Activities of glycogen phosphorylase, alanine aminotransferase and aspartate aminotransferase in adult worms of Litomosoides carinii recovered from pyridoxine deficient cotton rats (Sigmodon hispidus)

SummaryThis paper demonstrates that the activities of glycogen phosphorylase (GP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are reduced in adult worms of the filarial nematode Litomosoides carinii recovered from pyri-doxine-deficient cotton rats when compared to worms recovered from pyridoxine-sufficient controls. GP, ALT and AST activities were determined in adult worms L. carinii recovered from cotton rat hosts over a 20-week experimental period. Activities of GP, ALT and AST in the parasite showed a direct correlation with the dietary pyridoxine intake of their host. Throughout the experiment, enzyme activities were significantly lower (P < 0·001) in worms from rats fed a pyridoxine-free diet ad libitum that in worms from rats fed either a stock colony diet, a pyridoxine-free diet ad libitum with daily supplementation of 100 μg pyridoxine or limited amounts of pyridoxine-free diet with daily supplementation of 100 μg pyridoxine. The lower than normal activity of GP, ALT, AST and other enzymes dependent on the biologically active derivative of pyridoxine, the coenzyme pyridoxal-5-phosphate (PLP), interferes with the protein, carbohydrate and lipid metabolism of L. carinii and may in part cause the reduced establishment, development and growth of the parasite in pyridoxine-deficient hosts.

Integration of insect sterility and insecticides for control of Glossina morsitans morsitans Westwood (Diptera: Glossinidae) in Tanzania. I. Production of tsetse flies for release

A colony of Glossina morsitans morsitans Westw. was established in the laboratory in Tanga, Tanzania. After being expanded to the planned level of 60 000 flies, the stabilised colony was used to support a field trial using surplus males that were sterilised and released. The production system consisted of an adaptation of the in vivo rearing techniques developed at the Tsetse Research Laboratory, England. Goats were hosts for 90 % of the production; the balance was fed on rabbits. Techniques were developed to standardise the pupal off-take from stabilised colonies in each of three separate insectary units. Puparia were collected daily and kept separately until 52% emergence had occurred; these emerging flies, mostly females, were used to replenish the stock colony as needed. Further eclosion was prevented by chilling the remaining puparia (mostly males) quickly at 4°C and then storing at 10 ± 1°C for up to four days prior to irradiation and shipment to the field. About 68 % of the males produced were available for sterilisation. During the 15-month period of production in support of the field experiments, 1·3 million puparia were produced; 0·6 million of these puparia were released at a production cost of $220 per thousand.

EFFECTS OF EXOGENOUS OESTROGEN ALONE AND IN COMBINATION WITH PROGESTERONE ON PREGNANCY IN THE INTACT MINK

SUMMARY Daily injections of a combination of 2·4 mg. of progesterone and 24 μg. of oestradiol benzoate for 12–20 days, beginning 7 to 22 days post coitum in mink, failed to hasten ovo-implantation and increase litter size. On the contrary, it caused most of the females to be barren in comparison to similar non-treated animals in the stock colony. Daily injections of a combination of 8 mg. of progesterone and 2 μg. of oestrone for 12 days beginning four days post coitum likewise failed to hasten ovo-implantation in the mink, as shown by the length of pregnancy. This latter treatment caused a reduction rather than an increase in number of live kits at birth in the females that had litters. Daily injections of 3 μg. of oestrone for 8 days beginning 9 days post coitum caused a prolongation of the period of gestation, and presumably of the period of delay in ovo-nidation, and a reduction in number of kits alive at 7 days.

Post-partum breeding in the guinea-pig

Information relating to post-partum mating has been described in guinea-pigs kept in six small colonies containing variable numbers of the sexes running together continuously in floor pens of standard size. Litters were born on the floor and rearing was communal (Method 1). Three other like colonies were similarly maintained, except that the females in late pregnancy were separated from the male to avoid post-partum mating (Method 2). The conditions of farrowing and rearing were similar to those of Method 1. The data given by thirty-four sows of a closely recorded (stock) colony bred in units of six females and one boar, but in which every litter was born and reared under ‘cage’ conditions (Method 3), were used for comparative purposes only.Post-partum mating was considered to have occurred only when the interval between the births of any two consecutive litters of the same sow did not exceed 70 days. Of litters born under Method 1, 80% were conceived at post-partum oestrus; the mean gestation period was 68 days. The average inter-parturition interval of all sows breeding under Methods 1 and 2 was 74 and 118 days respectively. The optimal ratio of the sexes in a colony breeding by both methods was judged to be twelve females to one male.Litter size varied between 3·98 (Method 1) and 3·69 (Method 3) and by all three breeding methods, the proportion of young already dead or that died at birth was about 5%. Deaths were more common in summer months when litter size was maximal.The post-natal death-rate during the first 28 days of life among young reared communally (Methods 1 and 2) was 10% and was fivefold that observed in litters reared separately by their mothers (Method 3). This death-rate was highest during the winter months due to the difficulty of providing adequate amounts of fresh green vegetables.The annual output of young guinea-pigs from colonies bred under Method 1 was 62% greater than that from other colonies bred by Method 2. The more rapid sequence of littering did not affect the quality (body weight) of the young at birth or at weaning.Attention has been drawn to a possible deleterious effect of intensive breeding to the health of the females and their lessened resistance to infection. It has been suggested that, for this reason, the breeding life of the sows should be limited to 1 year.