Evidence for interference, coinfections, and intertypic virus enhancement of infection by ovine-caprine lentiviruses.

The ovine-caprine lentiviruses share nucleotide homology and serological properties in their gag-pol genes and gene products but constitute two distinct biological groups represented by ovine visna virus of Icelandic origin and by caprine arthritis-encephalitis and ovine progressive pneumonia viruses of U.S. origin. Two members of each group, visna 1514 and its antigenic variant LV1-1 in the first group and CAEV/CO and S93, a field isolate virus from a local arthritic sheep, in the second group, were examined in the present study in competitive-binding studies in fibroblast and macrophage cell cultures. The cultures were preinoculated with each of the four viruses and then reinoculated with either 1514 virus or CAEV/CO, labeled with [35S]methionine. Both 1514 and CAEV/CO caused homologous interference. LV1-1 and S93 viruses shared the interference patterns of 1514 and CAEV/CO, respectively. 1514 and LV1-1 did not interfere with binding of CAEV/CO. Similarly, CAEV/CO and S93 did not interfere with binding of 1514. Remarkably, certain combinations, such as S93 plus 1514, resulted in enhanced binding of the second virus. Other experiments showed that the enhancement in binding extended to enhancement in replication of the second virus. These latter data suggested that individual cells supported replication of both viruses. Further testing of this phenomenon showed that goats could be doubly infected with two noninterfering viruses, 1514 and CAEV/CO. The ability of noninterfering related lentiviruses to infect the same cell and also the same host animal may be important in the natural history of these viruses in providing ideal conditions for the development of new recombinant viruses.     

Trisomy 18q: 46,XX,-10,+der(10) t(10;18) (p15;q12) pat: a case report.

A 2-month-old female with intrauterine and postnatal growth retardation, multiple congenital anomalies, absent right kidney, congenital heart disease was investigated. Her karyotype revealed, 46,XX,-10,+der(10), t(10;18) (p15;q12) pat. The child died at 2 months 2 weeks. This is the third case of trisomy 18q resulting from translocation of chromosome 10 and 18.     

Efficient transgenic plant regeneration throughAgrobacterium-mediated transformation of Chickpea (Cicer arietinum L.)

Three genotypes of chickpea ICCV-1, ICCV-6 and a Desi (local) variety were tested for plant regeneration through multiple shoot production. The embryo axis was removed from mature seeds, the root meristem and the shoot apex were discarded. These explants were cultured on medium containing MS macro salts, 4X MS micro salts, I35 vitamins, 3.0 mg/1 BAP, 0.004 mg/1 NAA, 3% (w/v) sucrose and incubated at 26⁰C. The explants were transformed withAgrobacterium tumefaciens strain LBA4404 with binary vector pBI121 containing theuidA andnptIl genes. Multiple shoots were repeatedly selected with kanamycin. The selected kanamycin resistant shoots were rooted on MS medium supplemented with 0.05 mg/1 113A. The presumptive transformants histochemically stained positive for GUS. Additionally, nptll assay confirmed the expression ofnptII in kanamycin resistant plants. Transgenic plants were transferred to soil and grown in the green house.Abbreviations BAP 6-benzylamino purine - 2,4-D 2,4dichlorophenoxy acetic acid - IAA Indole acetic acid - IBA Indole butaric acid - NAA Naphthalene acetic acid     

Doubling protected land area may be inefficient at preserving the extent of undeveloped land and could cause substantial regional shifts in land use

Projection of land use and land-cover change is highly uncertain yet drives critical estimates of carbon emissions, climate change, and food and bioenergy production. We use new, spatially explicit land availability data in conjunction with a model sensitivity analysis to estimate the effects of additional land protection on land use and land cover. The land availability data include protected land and agricultural suitability and is incorporated into the Moirai land data system for initializing the Global Change Analysis Model. Overall, decreasing land availability is relatively inefficient at preserving undeveloped land while having considerable regional land-use impacts. Current amounts of protected area have little effect on land and crop production estimates, but including the spatial distribution of unsuitable (i.e., unavailable) land dramatically shifts bioenergy production from high northern latitudes to the rest of the world, compared with uniform availability. This highlights the importance of spatial heterogeneity in understanding and managing land change. Approximately doubling the current protected area to emulate a 30% protected area target may avoid land conversion by 2050 of less than half the newly protected extent while reducing bioenergy feedstock land by 10.4% and cropland and grazed pasture by over 3%. Regional bioenergy land may be reduced (increased) by up to 46% (36%), cropland reduced by up to 61%, pasture reduced by up to 100%, and harvested forest reduced by up to 35%. Only a few regions show notable gains in some undeveloped land types of up to 36%. Half of the regions can reach the target using only unsuitable land, which would minimize impacts on agriculture but may not meet conservation goals. Rather than focusing on an area target, a more robust approach may be to carefully select newly protected land to meet well-defined conservation goals while minimizing impacts to agriculture.     

Increased plasma corticosterone levels in bovine growth hormone (bGH) transgenic mice: Effects of ACTH,GH and IGF-I onin vitro adrenal corticosterone production

Previous work from our laboratory provided evidence for increased plasma corticosterone levels in mice transgenic for human and bovine growth hormone (GH). Corticosterone was elevated in both sexes, under both basal and ether-induced stress conditions. The objectives of the present study were to investigate thein vitro adrenal sensitivity to ACTH, GH and/or IGF-I in normal and bGH transgenic mice, to examine plasma corticosterone levels at different times of the day, and to determine plasma levels of ACTH in these animals. For the measurement of plasma corticosterone and ACTH levels, transgenic and normal siblings were housed 2 per cage and decapitated simultaneously within 20 seconds of the first disturbance of the cage. The corticosterone production byin vitro adrenal incubations did not differ between adrenals from normal and transgenic mice at the basal level or in the presence of different doses of ACTH. Growth hormone or IGF-I did not have any effect on corticosterone productionin vitro when given alone, and did not modify the effects of ACTH on the accumulation of corticosterone in the media. Plasma corticosterone concentrations were higher in transgenic than in normal animals in both morning and evening. Plasma concentrations of ACTH in animals killed in the morning were sharply increased in transgenic males as compared with their normal siblings. The results indicate that increased circulating levels of corticosterone in transgenic mice are not due to a potentiation of ACTH actions by GH or IGF-I, but rather to a chronic increase in plasma ACTH levels. The increase in ACTH is presumably a reflection of GH actions in the hypothalamic-pituitary system.     

Metabolism of activated oxygen in detached wheat and rye leaves and its relevance to the initiation of senescence

Pollen grains of Plumbago zeylanica L. were serially sectioned and examined using transmission electron microscopy to determine the three-dimensional organization of sperm cells within the microgametophyte and the quantity of membrane-bound organelles occurring within each cell. Sperm cells occur in pairs within each pollen grain, but are dimorphic, differing in size, morphology and organelle content. The larger of the two sperm cells (S_vn) is distinguished by the presence of a long (approx. 30 m) projection, which wraps around and lies within embayments of the vegetative nucleus. This cell contains numerous mitochondria, up to two plastids and, infrequently, microbodies. It is characterized by a larger volume and surface area and contains a larger nucleus than the other sperm cell. The second sperm cell (S_ua) is linked by plasmodesmata with the S_vn, but is unassociated with the vegetative nucleus. It is smaller and lacks a cellular projection. The S_ua contains relatively few mitochondria, but numerous (up to 46) plastids and more microbodies than the other sperm. The degree of dimorphism in their content of heritable cytoplasmic organelles must at fertilization result in nearly unidirectional transmission of sperm plastids into just one of the two female reproductive cells, and preferential transmission of sperm mitochondria into the other.Abbreviations S_ua sperm cell unassociated with the vegetative nucleus - S_vn sperm cell physically associated with the vegetative nucleus 1=Russell and Cass (1981)     

Nuclear DNA divergence among Lathyrus species

Among diploid Lathyrus species a threefold variation in nuclear DNA amount is attributable to differences in the amount of repetitive DNA. Cross reassociation among repetitive and among non-repetitive DNA fractions from different species shows substantial divergence in DNA composition. The divergence in base composition is correlated with nuclear DNA amount. The degree of divergence is of the same order of magnitude in both the repetitive and nonrepetitive fractions.     

Genomic changes associated with antigenic variation of visna virus. II. Common nucleotide sequence changes detected in variants from independent isolations

Naturally occurring antigenic variants of visna virus isolated from two persistently infected sheep have been compared using RNAase T₁ fingerprint analysis of the viral RNAs. All the viruses examined have oligonucleotide changes in the 3′-terminal region of the viral genome and many of the alterations are common among the variants of both sheep. There is progressive accumulation of point mutations in the 3′-terminal region of antigenically altered viruses isolated from persistently infected animals. In addition, antigenic variants isolated independently from another sheep contain the same altered oligonucleotides; the nucleotide sequences of these oligonucleotides are identical. These data strongly suggest that the alterations observed in the nucleotide sequence of the variants are related to the change in their antigenic character.