It often occurred to me that it would be advisable to try whether seedlings from cross-fertilized flowers were in any way superior to those from selffertilized flowers. . .. I ought to have reflected that such elaborate provisions favouring cross-fertilization, as we see in innumerable plants, would not have been acquired for the sake of gaining a distant and slight advantage, or of avoiding a distant and slight evil.

Differences in fitness between seedlings derived from cleistogamous and chasmogamous

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1558-5646.1984.tb00301.x

Differences in fitness between seedlings derived from cleistogamous and chasmogamous flowers in impatiens capensis.

In herpes simplex virus type 1 (HSV-1)-infected HEp-2 cells, amanitin added before or at various times after infection always reduced viral multiplication. Also, the three waves of transcription of HSV-1 DNA, which led to the synthesis of alpha, beta-, and gamma-polypeptides, were all sensitive to amanitin in HEp-2 cells, and the amanitin-sensitive RNA polymerase activities of isolated nuclei were equally sensitive to the inhibitor before and during the infection. On the contrary, HSV-1 DNA transcription was totally unaffected by amanitin in AR1/9-5B cells, a mutant subline of CHO cells that possesses an amanitin-resistant RNA polymerase B. Together, these results strongly suggest that HSV-1 DNA utilizes for its transcription a polymerase undistinguishable from host cell RNA polymerase B with respect to its sensitivity to amanitin.

Evidence that herpes simplex virus DNA is transcribed by cellular RNA polymerase B.

In recent years the term ‘icosahedral cytoplasmic deoxyribovirus’* has been used to describe a variety of viruses, including the iridescent viruses, the lymphocystis viruses, frog virus 3 and African swine fever virus (Granoff, 1969; Stoltz, 1971; Kelly, 1972a; Plowright, 1972). The term also serves to describe cauliflower mosaic virus and related viruses, but delineates these icosahedral viruses from the structurally complicated viruses — the pox viruses (Bergoin & Dales, 1971). The qualifications required for a virus to be considered as an ‘icosahedral cytoplasmic deoxyribovirus’ are by no means stringent — merely that the virus particle is icosahedral, replication occurs in the cytoplasm, and the virus contains DNA. We are of the opinion that the isolation of such viruses from a variety of sources has led a number of authors and authorities unwisely to assign such viruses into two groups (Wildy, 1971; Andrewes & Pereira, 1972). Subak-Sharpe (1971) has commented on the fact that viruses have a very limited range of morphologies.

Icosahedral Cytoplasmic Deoxyriboviruses

Interspecific hybridization among Hawaiian species ofCyrtandra (Gesneriaceae) was investigated using randomly amplified polymorphic DNA (RAPD) markers. Thirty-three different primers were used to investigate interspecific hybridization for 17 different putative hybrids based on morphological intermediacy and sympatry with putative parental species. RAPD data provided evidence for the hybrid origin of all putative hybrid taxa examined in this analysis. However, the patterns in the hybrid taxa were not found to be completely additive of the patterns found in the parental species. Markers missing in the hybrid taxa can be attributed to polymorphism in the populations of the parental species and the dominant nature of inheritance for RAPD markers. Unique markers found within hybrid taxa require further explanation but do not necessarily indicate that the taxa are not of hybrid origin. The implications suggest that these interspecific hybridization events had, and continue to have, an effect on the adaptive radiation and conservation biology ofCyrtandra.

Interspecific hybridization in natural populations of Cyrtandra ( Gesneriaceae ) on the Hawaiian Islands: Evidence from RAPD markers

FROG virus (FV-3) is one of a group of polyhedral DNA-containing viruses, isolated from normal, tumour and diseased tissues of a variety of amphibia, which replicate within the cytoplasm of infected cells1. FV-3 multiplies at 12° to 31° C, with a distinctive cytopathic effect, in cell cultures from both poikilothermic and homothermic (including human) vertebrates1,2. The properties of the virion and the characteristics of virus replication have been reviewed by Granoff1. The earliest demonstrable ovent in cells infected by FV-3 is a marked depression of cellular RNA synthesis, within 1 h of infection1,3.

Anna Mannini Palenzona

Papers

Selective inhibition of a nuclear RNA polymerase in cells infected with frog virus.