Chromosome studies in the red howler monkey, Alouatta seniculus stramineus (Platyrrhini, Primates): description of an X1X2Y1Y2/X1X1X2X2 sex-chromosome system and karyological comparisons with other subspecies

In the red howler monkey, Alouatta seniculus stramineus (2n = 47, 48, or 49), variations in diploid chromosome number are due to different numbers of microchromosomes. Males exhibit a Y;autosome translocation involving the short arm of an individual biarmed autosome. Consequently, the sex-chromosome constitution in the male is X1X2Y1Y2, with X1 representing the original X chromosome, X2 the biarmed autosome (No. 7), Y1 the Y;7p translocation product, and Y2 the acrocentric homolog of 7q. In the first meiotic division, a quadrivalent with a chain configuration can be observed in spermatocytes. Females have an X1X1X2X2 sex-chromosome constitution. Chromosome heteromorphisms were observed in pair 13, due to a pericentric inversion, and pair 19, due to the presence of constitutive heterochromatin. Microchromosomes, which varied in number between individuals, were also heterochromatic. NOR-staining was observed at two separate sites on a single chromosome pair (No. 10). A comparison of A.s. stramineus with A.s. macconnelli shows that these two subspecies have identical diploid chromosome numbers (47, 48, or 49), again due to a varying number of microchromosomes, and that they share a similar sex-chromosome constitution. Their karyotypes, however, are not identical, but can be derived from each other by a reciprocal translocation. Further comparisons with other A. seniculus subspecies reported in the literature indicate that this taxon is not karyologically uniform and that substantial chromosome shuffling has occurred between populations that have been considered to be subspecies by taxonomic criteria based on their morphometric attributes.     

The human endonexin II (ENX2) gene is located at 4q28----q32

A relatively recently identified family of structurally similar Ca2(+)-dependent phospholipid binding proteins is called the annexin gene family. At least seven genes are known, although their exact functions are unclear. The endonexin II gene (ENX2), one member of the gene family, is assigned to 4q28----q32 using both Southern transfer analysis of human x rodent somatic cell hybrid DNAs and in situ chromosome hybridization. One of the lipocortin II genes, another annexin, had previously been assigned to the long arm of chromosome 4.     

Isolation and identification of Cryptosporidium from various animals in Korea. III. Identification of Cryptosporidium baileyi from Korean chicken]

Each of SPF chicken (Hi-Line strain, 2-day-old males) was inoculated with 2.5 or 5 x 10(4) oocysts by stomach tube. The oocyst was the medium type of Cryptosporidium previously isolated from Korean chicken origin, and passed in 2-day-old SPF chicken. The patterns of oocyst discharge were monitored daily, and in order to observe the ultrastructure of the developmental stages, the bursa of Fabricius of the chicken was examined by transmission electron microscopy (TEM) on the 12th day postinoculation. The prepatent period for 8 chicken was 5.9 days postinoculation on the average, and the patent period was 12.9 days. The number of oocysts discharged per day for the chicken was reached peak on day 12 postinoculation on the average. A large number of oocysts was found in fecal samples obtained from inoculated chicken on days 8-14 postinoculation. The ultrastructural feature of almost every developmental stage of the medium type from chicken was very similar to that of Cryptosporidium previously isolated from mammalia including human and birds except for the attachment site of C. muris to the mucus cell from mammalia, but dimension of the oocysts from fecal samples of the medium type was different from those of C. meleagridis and mammalia origin. The above results reveal that the medium type of Cryptosporidium of Korean chicken origin is identified as Cryptosporidium baileyi.     

Isolation and identification of Cryptosporidium from various animals in Korea. I. Prevalence of Cryptosporidium in various animals

Cryptosporidium, a coccidian protozoa, commonly causes a self-limiting diarrheal illness in humans and animals. Fecal samples from various animals in Chonbuk district were observed using Sheather's flotation technique, Kinyoun's modified acid-fast staining, and osmic acid pre-fixed Giemsa staining. The oocysts were detected in 74 cages (29.6%) out of 250 cages of mature mice, 26 (13.3%) out of 195 mature house rats, 75(15.0%) out of 4-week-old 500 fowls, 98(19.9%) out of 6 to 8-month-old 500 pigs, and 111(22.2%) out of 2 to 5-year-old 500 dairy cattle, respectively. The degree of prevalence was slight in general, but actual prevalence was higher than infection rate because the detection rates were higher in repeated-preparation examinations in comparison to the first examination. Meanwhile, large and small types of oocysts were detected from mice, house rats, pigs, and cattle, and medium type from fowls.     

Epidemiology of hydatid disease in Sardinia: a study of fertility of cysts in sheep

Hydatidosis, caused by Echinococcus granulosus, is a cyclozoonotic disease of economic significance in Sardinia. The life-cycle involves stray and sheep dogs as definitive hosts and sheep, pigs, goats and cattle as intermediate hosts. The most important intermediate host is sheep, due to home slaughtering with ready access of the viscera to dogs. This survey was undertaken in 1987 to ascertain the epidemiological significance of sheep in maintaining the life-cycle. A total of 700 (91.3%) of 767 sheep harboured hydatid cysts. The frequency distribution of the number of hydatid cysts was over-dispersed. Of 497 infected sheep, 7.6% had fertile cysts, 75.7% sterile cysts and 16.7% fertile + sterile cysts.     

Satellite DNA sequences in the New World primateCebus apella (Platyrrhini,Primates)

Two satellite DNAs, designated CapA and CapB, were isolated from the neotropical primate,Cebus apella. The satellites exhibit nonoverlapping distributions onC. apella chromosomes. CapA is a major component of interstitial regions of constitutive heterochromatin, a very large block of heterochromatin comprising most of the long arm of chromosome 11, and some telomeres. The CapA monomer has a length of about 1500 bp and appears recently to have undergone an amplification episode in theC. apella genome. CapA-like sequences are probably present in members of the family Cebidae (to whichC. apella belongs), but not in members of the family Callitrichidae (marmosets). CapB sequences can be detected at the centromeres of manyC. apella chromosomes, and similar sequences are present in all neotropical primates. The 342 bp CapB monomer shares 60%–64% sequence identity with several alpha satellite sequences of human origin. Because of its structure, sequence, and location, it appears that CapB is the New World primate homolog of Old World primate alpha satellite DNA.     

Late DNA replication in rhesus monkey (Macaca mulatta) chromosomes

A study of the pattern of late DNA replication in rhesus monkey chromosomes showed evident similarities with man. This must be a consequence of the evolutionary conservation of replication patterns in primate chromosomes, as it has been demonstrated in the great apes, in Cebus, and man. However, the pattern of late replication of the allocyclic X chromosome in lymphocytes of female rhesus monkey was identical with the fibroblast pattern in man, and with the pattern found in only 5 to 20% of human lymphocytes.     

A polymorphic structural rearrangement in the chromosomes of two populations of orangutan

A rearranged chromosome 9 was found in 12 of 23 specimens of orangutan, 4 of Bornean and 8 of Sumatran origin. Nine animals were heterozygous, and 3 were homozygous carriers for the variant chromosome, which was also traced in 4 other animals not studied by us. This type of chromosome rearrangement has been previously described (Seuánez et al., 1976) and is probably the same chromosome shown by Lucas et al. (1973) and reported by Turleau et al. (1975) in other specimens. There is obviously a very high incidence of this variant chromosome 9 in Pongo pygmaeus, and it is unlikely that it could result from independent rearrangements occurring in unrelated specimens from two geographically isolated populations (Sumatran and Bornean). It is concluded that the rearrangement is of ancient origin and that it has been maintained in the populations of Pongo as a balanced polymorphism. This type of complex rearrangement resulting from two pericentric inversions, one inside the other, is compared with certain sporadic pericentric inversions in the human complement, with pericentric inversions which are polymorphic in other mammals, and with pericentric inversions involved in chromosome evolution in the Hominoidea.     

Vascular Calcifying Progenitor Cells Possess Bidirectional Differentiation Potentials

Vascular calcification is an advanced feature of atherosclerosis for which no effective therapy is available. To investigate the modulation or reversal of calcification, we identified calcifying progenitor cells and investigated their calcifying/decalcifying potentials. Cells from the aortas of mice were sorted into four groups using Sca-1 and PDGFRα markers. Sca-1⁺ (Sca-1⁺/PDGFRα⁺ and Sca-1⁺/PDGFRα⁻) progenitor cells exhibited greater osteoblastic differentiation potentials than Sca-1⁻ (Sca-1⁻/PDGFRα⁺ and Sca-1⁻/PDGFRα⁻) progenitor cells. Among Sca-1⁺ progenitor populations, Sca-1⁺/PDGFRα⁻ cells possessed bidirectional differentiation potentials towards both osteoblastic and osteoclastic lineages, whereas Sca-1⁺/PDGFRα⁺ cells differentiated into an osteoblastic lineage unidirectionally. When treated with a peroxisome proliferator activated receptor γ (PPARγ) agonist, Sca-1⁺/PDGFRα⁻ cells preferentially differentiated into osteoclast-like cells. Sca-1⁺ progenitor cells in the artery originated from the bone marrow (BM) and could be clonally expanded. Vessel-resident BM-derived Sca-1⁺ calcifying progenitor cells displayed nonhematopoietic, mesenchymal characteristics. To evaluate the modulation of in vivo calcification, we established models of ectopic and atherosclerotic calcification. Computed tomography indicated that Sca-1⁺ progenitor cells increased the volume and calcium scores of ectopic calcification. However, Sca-1⁺/PDGFRα⁻ cells treated with a PPARγ agonist decreased bone formation 2-fold compared with untreated cells. Systemic infusion of Sca-1⁺/PDGFRα⁻ cells into Apoe^−/− mice increased the severity of calcified atherosclerotic plaques. However, Sca-1⁺/PDGFRα⁻ cells in which PPARγ was activated displayed markedly decreased plaque severity. Immunofluorescent staining indicated that Sca-1⁺/PDGFRα⁻ cells mainly expressed osteocalcin; however, activation of PPARγ triggered receptor activator for nuclear factor-κB (RANK) expression, indicating their bidirectional fate in vivo. These findings suggest that a subtype of BM-derived and vessel-resident progenitor cells offer a therapeutic target for the prevention of vascular calcification and that PPARγ activation may be an option to reverse calcification.