We determined partial cDNA sequences of four immunoglobulin (Ig) classes-IgM, IgG1, IgE, and IgA-of Mongolian gerbil (Meriones unguiculatus). Each deduced Ig heavy-chain constant (IGHC) region-Cµ, Cγ1, Cε, and Cα-is structurally similar to its counterparts in the mouse and rat, and phylogenetic analysis suggests that the gerbil Igs are evolutionarily close to their counterparts. In spite of the high sequence homology to the other rodent Cγ sequences, the gerbil Cγ1 sequence differs from our previously reported Cγ2. This result indicates that the gerbil has at least two IgG subclasses. These four gerbil IGHC cDNA sequences will be useful for determining gerbil Ig isotypes and examining the expression of gerbil Ig mRNAs in response to parasitic and bacterial infections.
Bilateral ovariectomy (Ovx) was carried out on day 20 of pregnancy in Mongolian gerbils (Meriones unguiculatus). The body weights of all groups tended to decrease on the day after the operation, and the decrease was significant in the group that was ovariectomized and given vehicle (Ovx + vehicle group). The body weight in this group never recovered until autopsy on day 24, which is normally 1 day before parturition. No fetuses survived to the time of autopsy in any of the animals of the Ovx + vehicle group. Daily administration of 4 mg of progesterone (P4) prevented the termination of pregnancy in Ovx animals, but 1 mg did not. Treatment with estradiol 17β (E2) in addition to 4 mg of P4 tended to result in a lower rate of fetal survival than that of the Ovx group treated with 4 mg of P4 alone. With regard to fetal weight, treatment with 4 mg of P4 resulted in the same weight as in the sham-operated controls, but the addition of 0.2 or 1 μg of E2 to the 4 mg of P4 resulted in a significantly lower weight than that of fetuses in the 4 mg of P4 group. The present study suggests that adequate maintenance of pregnancy in ovariectomized gerbils can be achieved by daily treatment with 4 mg of P4 alone. Moreover, treatment with 0.2 or 1 μg of E2 in addition to 4 mg of P4 caused a deterioration in the maintenance of gestation, in contrast to the effects in rats, mice and hamsters.
1. We established a PCR-RFLP analysis targeting R77H mutation in the Tyr gene as a more effective genotyping to identify carrier (C/c) with the albino allele and the agouti phenotypes. 2. Our breeding system, which targets the R77H site, is a useful cue for detecting C/c carriers with the agouti-phenotype and helps us to obtain albinos by mating agouti-phenotype carriers.
To investigate factors involved in the secretion of protoporphyrin IX (PpIX), a superficial eggshell pigment, from shell gland epithelial cells of Japanese quail, we cultured cells in Ham’s F12 medium with calcium chloride and quail plasma. The addition of hormones (prostaglandin F2α, progesterone, estradiol-17β) to the medium did not change the PpIX concentration in the culture supernatant, but changing the calcium chloride (CaCl2) concentration did: a lower concentration of CaCl2 led to a higher PpIX concentration; 0 mM CaCl2 enhanced the secretion of PpIX from epithelial cells prepared at 5 or 7 mM CaCl2. The result suggests that a drop in concentration of CaCl2 mimics the end of shell calcification and stimulates rapid secretion of PpIX in vivo. Bovine serum albumin was almost as effective as quail plasma for PpIX secretion in culture, and would facilitate further study of the mechanism of PpIX secretion.
ABSTRACT The present study was conducted to determine the in vitro progesterone (P 4 ) production by Mongolian gerbil ( Meriones unguiculatus ) corpus luteum (CL) on days 9, 18 and 22 of pregnancy in comparison with rat CL on days 9 and 16. The culture medium of one CL per well of a 96‐well plate was changed after 4 h incubation and the CL were further cultured for 24 h. The P 4 in serum and in the medium were measured by enzyme immunoassay system. Gerbil CL weight measured after 24 h incubation was at the same level for all 3 days of pregnancy and significantly different from that of the rat CL for the 2 days of pregnancy. The serum P 4 level in gerbils was high in early pregnancy and decreased in advanced days of pregnancy. In contrast, the P 4 in rats was higher in the latter half of pregnancy. In vitro P 4 production by a single CL after 4 h incubation decreased significantly during the days of pregnancy in both the gerbil and the rat. P 4 values produced by the gerbil CL for 24 h incubation were significantly higher than after 4 h incubation in all 3 days of pregnancy, however, there was no difference between the two incubation time groups in the rat. In vitro P 4 production by CL correlated well with the serum P 4 level on the 3 days of pregnancy in the gerbil. In the rat, however, the relationship was inversed between the two parameters. The correlation in this experiment suggested that CL is the sole source of P 4 for the maintenance of the gerbil pregnancy, with the result of abortion after an ovariectomy on day 20 of pregnancy as described in our previous report.
Abstract Some aspects of the effects of cyclosporin A (CsA) on the chicken immune system are described. High serum levels of CsA could be maintained by i.m. administration of the drug in a neutral oil (Miglyol 812) every three days. After a transient decrease in peripheral blood T lymphocytes, the blood picture remained normal over a dosage period of three weeks. Mitogenic stimulation of the peripheral blood lymphocytes was strongly depressed, however. Whereas there was a trend to decreased primary immune response of T‐dependent (sheep red blood cells, human γ‐globulins) and T‐independent (B. abortus) antigens, high variation in individual response made this trend statistically insignificant, except for the response to B. abortus at a CsA dose of 50 mg/kg. There was also a trend to decreased secondary IgM response to T‐dependent antigens and increased IgM response to the T‐independent antigens. The clearest alteration in secondary humoral response was the block of IgG (+ IgA) response to both categories of antigens. There was only a slight decrease in body weight after 3 weeks of CsA administration, a decrease in the absolute weights of thymus and spleen (but not bursa) at 50 mg/kg and a decrease in relative weight only in the case of the thymus. Despite these changes, the histology of the thymus, particularly the cortex, was normal. The major histological changes were in the spleen where there was a depletion of the periarteriolar lymphytic sheath, a marked increase in granulated cells, a decrease in germinal centers, and the appearance of large numbers of Mott cells. This type of cell was occasionally found in bone marrow and very rarely in liver and the mucosal connective tissue of the bursa, tissues which were otherwise normal. The Mott cell may arise as a result of the changes in T cell subsets leading to an uncontrolled production of nonsecreted immunoglobulins.
