KARYO-RACES IN SPINACIA OLERACEA

Bose , Smritimoy , and Jules Janick . (Purdue U., Lafayette, Ind.) Karyo-races in Spinacia oleracea. Amer. Jour. Bot. 48(3): 238–241. Illus. 1961.—Cytological analysis of chromosome 1 of Spinacia oleracea, which contains the XY factor pair, revealed the existence of 3 distinct morphological types. The “standard” chromosome 1, the longest of the complement, is heterobrachial with one arm being about twice as long as the other. The most prevalent situation is for this “standard” chromosome pair to be homomorphic in staminate, monoecious, or pistillate plants. Some staminate and pistillate plants in the varieties ‘Spica’ and ‘Universal’ were found to be heteromorphic for the standard chromosome and a variant type, distinguished by a satellite on the short arm. In a cross derived from an accession PI 169671 from Turkey, which segregated for monoecious and pistillate types, half of the plants, irrespective of sex, were homomorphic for the standard chromosome and half were heteromorphic. The non-standard chromosome was longer and isobrachial, the added length apparently due to an additional segment on the short arm of the “standard” chromosome. Plants homomorphic for the satellited and isobrachial chromosome have been obtained.     

Genome Wide Association Analysis Reveals New Production Trait Genes in a Male Duroc Population

In this study, 796 male Duroc pigs were used to identify genomic regions controlling growth traits. Three production traits were studied: food conversion ratio, days to 100 KG, and average daily gain, using a panel of 39,436 single nucleotide polymorphisms. In total, we detected 11 genome-wide and 162 chromosome-wide single nucleotide polymorphism trait associations. The Gene ontology analysis identified 14 candidate genes close to significant single nucleotide polymorphisms, with growth-related functions: six for days to 100 KG (WT1, FBXO3, DOCK7, PPP3CA, AGPAT9, and NKX6-1), seven for food conversion ratio (MAP2, TBX15, IVL, ARL15, CPS1, VWC2L, and VAV3), and one for average daily gain (COL27A1). Gene ontology analysis indicated that most of the candidate genes are involved in muscle, fat, bone or nervous system development, nutrient absorption, and metabolism, which are all either directly or indirectly related to growth traits in pigs. Additionally, we found four haplotype blocks composed of suggestive single nucleotide polymorphisms located in the growth trait-related quantitative trait loci and further narrowed down the ranges, the largest of which decreased by ~60 Mb. Hence, our results could be used to improve pig production traits by increasing the frequency of favorable alleles via artificial selection.     

La régénération des ovaires chez Polycelis nigra [Ehrenb.]

Sans résumé     

The isomers of cocaine and tropacocaine: Effect on 3H-catecholamine uptake by rat brain synaptosomes

Compared to (+)-$\text{pseudo}$cocaine, (?)-cocaine was 20 times more potent in inhibiting uptake of ³H-norepinephrine (³HNE) by cortical synaptosomes and 66 times more potent with respect to ³H-dopamine (³HDA) uptake by striatal synaptosomes. Although the tropacocaine isomers were equipotent as inhibitors of ³HNE uptake in the cortex, tropacocaine was 3.9 times more potent as an inhibitor of ³HDa uptake in the striatum than $\text{pseudo}$tropococaine. A major known cocaine metabolite, benzoylecgonine failed to inhibit the accumulation of ³HNE and ³HDA by synaptosomes from the cortex and striatum, respectively. The implications of these findings in relation to the motor stimulation seen with (?)-cocaine, (+)-$\text{pseudo}$cocaine and benzoylecgonine in rats are discussed.     

Adult ovaries of Locusta migratoria contain the sequence of biosynthetic intermediates for ecdysone

Ovaries of adult $\text{Locusta migratoria}$ have recently been shown to produce impressive amounts of ecdysone together with low polarity ecdysteroids, some of which cross-react with ecdysone in our RIA. A gas chromatographic-mass spectrometric analysis of extracts from ovaries of $\text{Locusta}$ has shown the presence of following compounds (less polar than ecdysone): 2-deoxy-ecdysone, 2,22-bis-deoxy-ecdysone, 2, 22, 2 5-tri-deoxy-ecdysone, 2, 14, 22, 2 5-tetra-deoxy-ecdysone. No other related ecdysteroids were present in our extracts. Cholesterol is used by $\text{Locusta}$ ovaries as a precursor for ecdysone biosynthesis, as our previous studies with labelled products have shown, and we propose that the compounds detected in the present work represent biosynthetic intermediates between cholesterol and ecdysone in $\text{Locusta}$ ovaries.