The Influence of Auxin and Cytokinin on Proliferation and Morphology of Somatic Embryos of Picea abies (L.) Karst

Embryogenic cell-lines of Picea abies were initiated from maturezygotic embryos and cultured on medium containing 2,4-D andBA The cell-lines were categorized into two main groups (solar/polarand undeveloped embryos), based on the morphology of the somaticembryos and their ability to go through a maturation processwhen treated with ABA The cell-lines were transferred to mediacontaining (1) 2,4-D and BA, (2) only BA, (3) only 2,4-D or(4) no growth regulators When cultured on a medium containingboth 2,4-D and BA new somatic embryos were continually formedIn contrast, when they were cultured without one or both ofthe growth regulators no new somatic embryos were formed Solar/polarand undeveloped embryos responded in the same way On a mediumcontaining only BA the somatic embryos already present increasedin size and developed an extremely large embryonic region Ona medium containing only 2,4-D the embryos already present becamedisorganized into loose aggregates When transferred from a mediumcontaining both 2,4-D and BA to one containing ABA, mature somaticembryos developed from the solar/polar type but not from theundeveloped type The ability of the solar/polar somatic embryosto go through a maturation process decreased when they wereprecultured on a medium lacking auxin and was lost when theywere precultured on medium lacking cytokinin The cell-linescontaining undeveloped somatic embryos produced mature somaticembryos in one cell-line out of three that had been culturedon the medium containing only BA Auxin, cytokinin, embryogenic cultures, Norway spruce, somatic embryos, Picea abies (L.) Karst     

Interstitial Dorvilleidae (Annelida, Polychaeta) from Europe, Australia and New Zealand

Four dorvilleid species new to science are described from intertidal and subtidal sandy sediments. For three of them new genera are erected: Coralliotrocha natans gen. et sp.n., Microdorvillea otagensis gen. et sp.n. and Pusillotrocha Åkessoni gen. et sp.n. One species represents the first record of the genus Pettiboneia from Australia, P. australiensis sp.n. Ophryotrocha minuta Levi, 1954 redescribed from Helgoland is transferred to a different genus, Arenotrocha gen.n. The present taxa belong to a morphological series of species with an increasing degree of neoteny in the family Dorvilleidae.     

Clinical Studies and Physiological Properties of Hopkins-2 Haemoglobin

HAEMOGLOBIN Hopkins-2 (Ho-2) was discovered in a family in which haemoglobin S was also present¹. Independent segregation of the two abnormal haemoglobins provided the first convincing evidence that two genetic loci are concerned with synthesis of the haemoglobin molecule^1,2. Subsequently, evidence was obtained that the abnormality in haemoglobin Ho-2 is in the alpha chain³, whereas the lesion in haemoglobin S is in the beta chain of globin. We have reported the structural abnormality in Ho-2 and we now present a revised pedigree and the clinical status of carriers; we attempt to relate these findings to functional abnormalities exhibited by the haemoglobin.