Enzyme Variation of Eimeria arizonensis from Peromyscus truei and P. boylii

ABSTRACT. Cricetid rodents, Peromyscus truei and P. boylii , were inoculated with sporulated oocysts of Eimeria arizonensis collected from wild P. truei maintained in the lab. In P. truei the prepatent period was 4–5 days, the patent period was 9–11 days, and sporulated oocysts were 21.5 × 25.0 (20–23 × 24–26) μm with sporocysts 7.7 × 12.0 (6–8 × 10–13) pm. In P. boylii the prepatent period was 6–7 days, the patent period was 8–9 days, and sporulated oocysts were 20.1 × 23.2 (18–22 × 21–24) pm with sporocysts 6.8 × 10.0 (5–8 × 9–12) pm. Sporulated oocysts from both host species were used in direct side-by-side comparison of isozyme banding patterns using protein electrophoresis. The parasite has polytypic loci for leucine aminopeptidase (LAP), lactate dehydrogenase (LDH), and 6-phosphogluconate dehydrogenase (6-PGD). In oocysts from P. truei , LAP showed one band with fast migration and LDH and 6-PGD each showed two bands, one with fast and one with slow migration. In oocysts from P. boylii , LAP and LDH each had one band with slow migration and 6-PGD had one band with moderate migration. Oocysts of E. arizonensis collected from P. boylii were used to inoculate P. truei. The prepatent and patent periods, structural measurements, and isozyrne banding patterns of the resultant oocysts were the same as those from P. truei when inoculated with oocysts from P. truei.     

Comparative anatomy and systematics of woody Saxifragaceae. Aphanopetalum Endl.

The floral and vegetative anatomy of the small Australian genus Aphanopetalum were studied. Wood is described for the first time and is characterized by predominantly solitary pores, scalariform vessel element perforation plates with low bar numbers, imperforate tracheary elements with distinctly bordered pits, sparse axial parenchyma, and a combination of homocellular and heterocellular rayS. Starch occurs in both axial and ray parenchyma of the wood. Stems possess unilacunar, one-trace nodes and the uncommon feature of an endodermis with well-defined Casparian stripS. Leaves have anomocytic stomata, a bifacial mesophyll and semicraspedodromous venation or a combination of semicraspedodromous and brochidodromous venation. The tetramerous flowers are apetalous or have minute petals. The compound, half-inferior gynoecium consists of essentially totally united carpels. The pattern of floral vascularization resembles different Saxifragaceae sensu lalo in that the compound sepal-plane and petal-plane traces give rise to staman bundles as well as sepal, petal, and carpel wall venation in their respective planes. The ventral ovarian bundles are fused into a single ventral complex that subdivides at the top of the ovary to form ventral bundles and to supply the one ovule in each locule. Vegetative and floral features provide compelling evidence to suggest that Aphanopetalum has its nearest relatives among the Saxifragaceae sensu lato rather than Cunoniaceae. The genus is probably best treated as forming its own subfamily (or family) among the saxifragaean alliance.     

Alternative Reproductive Tactics in Spiders

The comparative study of reproduction at the level of populationand individual is a relatively recent development in spiderresearch. Such study is necessary to describe and examine alternativereproductive tactics. Female spider tactics are related to adaptationsfor a carnivorous mode of feeding. Being the larger of the sexes,the female has the alternative of mating with or preying uponattending males. In web building spiders, which are generallysolitary, other female alternatives are related to characteristicsof a web used in prey capture. These alternatives include differentresponses when defending the web, and individually buildingthe web so that it does or does not contact another. Tacticsmay vary in communal species which build a sheet-like structure,as females may remain in the colony or emigrate and establisha small web. Male spiders usually search for females, and matingoccurs on or near a female retreat or web. A male may show differentalternatives in mate searching, demonstrate various courtshipand copulatory tactics, copulate or feed on the female's preywhile she feeds, and guard the female after mating or departand search for another female. Certain characteristics of femalesare related to these male alternatives, these characteristicsbeing: larger size and longer life expectancy as compared withthe male, carnivorous feeding, and sexual receptivity. Maleweb spiders may also use alternatives while defending positionon the female web. These alternatives are related to the designand placement of the web, and occasional web abandonment bythe female. Relevant literature is reviewed and research suggested.     

AN ANTIGEN OF CHONDROITIN SULFATE PROTEOGLYCAN; A MARKER FOR CARTILAGE DIFFERENTIATION

Antisera to the chondroitin sulfate proteoglycan complex (CPG) of cartilage were used to study the specificity of the CPG-associated antigen as a biochemical marker for cartilage differentiation and to study the expression of differentiation by cultured chondrocytes. Of 7 tissues tested, antigen giving an identity reaction with this protein could be detected by the Ouchterlony double diffusion test in extracts of sternum and brain of 14-day chick embryos. Extracts of 2 non-cartilage tissues gave a reaction indicating that they contain a related, but not identical antigen.
Ouchterlony double diffusion tests showed that extracts of morphologically differentiated chondrocytes cultured in vitro contain the CPG-associated antigen. The radio-precipitin test, used to quantitate the rate of synthesis of this antigen, provided a measure of cartilage phenotype expression in culture. The cultured chondrocytes synthesized antigenic protein at a rate similar to that of 14-day sternum. In contrast to intact cartilage, however, the cultured chondrocytes released much of the newly synthesized antigen into the medium.
The possibility was explored that synthesis of the CPG-associated antigen might be characteristic of all cells in culture, and not a specific expression of the cartilage phenotype. However, skin fibroblast cultures only contained detectable antigen of the "partially identical" type.     

Regulation of Amino Acid Uptake into Oat Mesophyll Cells: A Comparison between Protoplasts and Leaf Segments

The uptake of -aminoisobutyric acid (AIB) into protoplasts andinto 1 cm sections of leaves from 7 d old light-grown oats (Avenasativa L. cv. ‘Garry’) was studied. Both protoplastsand leaf sections with cuticle and epidermis removed accumulatedAIB against a concentration gradient although the rate of uptakeinto protoplasts was one-third to one-sixth that into leaf sections.AIB uptake into both protoplasts and leaf cells in situ wasstimulated by ‘aging,’ and low pH, and inhibitedby osmotic shock, respiratory poisons, and KCl concentrationsabove 1 mM. It was concluded that the rate of uptake of AIBand its accumulation ratio could be accounted for by the energyinherent in the proton-motive force, the proton-motive forcebeing the sum of the pH gradient and potential difference acrossthe plasma membrane. The similarities between oat mesophyllprotoplasts and leaf cells in situ suggest that these protoplastsare suitable material for the study of certain membrane-regulatedevents.