Development of Eimeria alabamensis from Cattle in Mammalian Cell Cultures*

SYNOPSIS. Monolayer primary cultures of cells from bovine embryonic intestine (BEInt), kidney (BEK), spleen (BES), and thyroid (BETy) and cell line cultures of embryonic bovine trachea (EBTr) and synovium (BESy) as well as established cell line cultures of bovine kidney (Madin-Darby, MDBK), human intestine (Int 407) and Syrian hamster kidney (BHK) were inoculated with freshly excysted sporozoites of Eimeria alabamensis and observed for 4–5 days. Sporozoites penetrated all cell types; during the 1st 24 hr, intracellular sporozoites, trophozoites and binucleate schizonts were seen in all cell cultures. Mature schizonts were more numerous in BES and MDBK cells than in the others. Large schizonts, 14.2 (11–18.5) by 10.2 μ (8.5–11), with 6–14 short, stubby merozoites (each with 2 refractile bodies) occurred at 2 and 3 days in all cells except BESy, Int 407, and BHK. Small schizonts, 9.7 (5.5–13) by 6 μ (5–8.5), with 6–10 long, slender merozoites (each with 2 refractile bodies) were found 3 days after inoculation in all cell types. At 4 days, some intracytoplasmic merozoites and a few intranuclear 2nd generation trophozoites were found. After 4 days post-inoculation, intracellular parasites were rarely seen and these were apparently degenerate. Development within the host cell nucleus, the normal site of development in the host animal, was observed infrequently in cell cultures. Intranuclear sporozoites, found no earlier than 2 days after inoculation, developed similarly to those in the cytoplasm, and small intranuclear schizonts with 6–10 merozoites (each with 2 refractile bodies) occurred after 3 days in culture.     

Eimeria balphae n. sp. from the Ord Kangaroo Rat Dipodomys ordii*

SYNOPSIS. Eimeria balphae n. sp. is described from the Ord kangaroo rat Dipodomys ordii. The sporulated oocysts are broadly ellipsoidal to ovoid, averaging 16.7 by 14.3 μ. A single, large, homogenous body represents the oocyst residuum. A polar granule is present. There is no micropyle. The ovoid sporocysts average 8.7 by 5.9 μ. The sporocyst residuum is composed of 7–14 round, clear granules. This species of Eimeria was found in 1 of 82 D. ordii in northwestern Utah.     

Alterations of Adrenal Cortex and Thyroid in Mice with Congenital Absence of the Thymus

THE possible role of endocrine factors in the thymus and their control by hormones of the adenohypophysis or its target glands has been investigated extensively in animal models. These include mice whose pituitary function has been inhibited or blocked by anti-pituitary serum^1–3 or anti-growth-hormone serum^4–6, neonatally thymectomized mice^1,3,7–9 and the genetically hypopituitary dwarf mice with thymus atrophy^10–12. Further opportunities have been offered by the observation that genetically hairless “nude” mice (genetic symbol: nu)¹³ have no thymus^14,15.     

Eimeria utahensis sp. n. from Kangaroo Rats (Dipodomys ordii and D. microps) in Northwestern Utah*

SYNOPSIS. The sporulated oocysts of Eimeria utahensis sp. n. from 2 species of kangaroo rats in northwestern Utah are described. The oocysts averaged 42.0 by 39.3 μ, and had rough, yellow-brown walls, about 3 μ thick. In each sporocyst, a substiedal body was seen beneath the Stieda body; this is the 1st report of such a structure in any Eimeria species. E. utahensis was found in 3.6% of 196 Dipodomys ordii and 19.4% of 36 D. microps. The incidence was higher in young adult than in adult Ord kangaroo rats and lowest in juveniles; in D. microps only adults were infected. The mean prepatent period was 9.8 days. The patent period could not be determined because of apparent reinfections; there was no evidence of immunity.     

Polymorphic microsatellite loci for Diaprepes root weevil (Diaprepes abbreviatus L.)

Diaprepes abbreviatus (L.) is an insect pest of the US agriculture that originated from the Caribbean islands. Larvae are of economic importance in both nursery and commercial citrus plantings due to root feeding. Eight polymorphic microsatellite markers were developed from a (CA)_n‐enriched genomic library of Diaprepes root weevil. Three to eight alleles were observed for each locus during screening of 17 to 25 individuals. Observed and expected heterozygosities ranged from 0.182 to 0.864 and 0.587 to 0.835, respectively. These markers will be useful to characterize the genetic variability and track the migration patterns of populations of D. abbreviatus (L.).     

Natural variation and QTL analysis for cationic mineral content in seeds of Arabidopsis thaliana

Naturally occurring genetic variation for contents of cationic minerals in seeds of Arabidopsis thaliana was studied by screening a series of accessions (ecotypes) for Ca, Fe, K, Mg, Mn, Na, Zn, and for total contents of P. Variation was observed for all minerals and correlations between contents of various minerals were present, most noticeably between Ca and Mg, P and Mg, and P and Mn. The genetic basis of this variation was further studied by QTL analysis, using the Landsberg erecta (Ler) × Cape Verde Islands (Cvi) recombinant inbred population. For all minerals, except Na, one or more QTL were detected, explaining up to 78% of the variation. The map positions of several QTL were confirmed by analysis of near isogenic lines, carrying small Cvi introgressions in Ler background. Interesting co‐locations of QTL suggest pleiotropic effects, due to physiological coupling of the accumulation of certain minerals or to linkage of different genes. By comparing the map positions of QTL with the positions of genes expected to play a role in cation translocation, several candidate genes are suggested.