Host range restrictions of oncogenes: myc genes transform avian but not mammalian cells and mht/raf genes transform mammalian but not avian cells.

Abstract

The host range of retroviral oncogenes is naturally limited by the host range of the retroviral vector.

Satiation and Stress-Induced Hypophagia: Examining the Role of Hindbrain Neurons Expressing Prolactin-Releasing Peptide or Glucagon-Like Peptide 1

“…Direct descending projections from the cortex, limbic forebrain, and hypothalamus to cNST regions where PrRP and GLP-1 neurons reside provide a route through which emotional and cognitive events can modulate visceral and ingestive responses to diverse threats and opportunities to which the organism is exposed, including conditioned responses that are based on past experience (Sawchenko, 1983; Li et al, 1996; Li and Sawchenko, 1998; Woods and Ramsay, 2000; Dayas and Day, 2001; Taché et al, 2001; Buller et al, 2003; Dayas et al, 2004; Price, 2005; Blevins and Baskin, 2010). In turn, ascending projections from GLP-1 and NA neurons, including PrRP neurons, provide a route through which interoceptive feedback from the gastrointestinal tract and other organ systems can shape hypothalamic and limbic forebrain functions (Sawchenko, 1983; Loewy, 1990; Onaka et al, 1995, 2010; Blessing, 1997; Rinaman and Schwartz, 2004).…”

“…CRH is the principal and obligate hypophysiotropic peptide driving the HPA axis under basal conditions and in response to homeostatic challenge (Plotsky et al, 1989; Watts, 1996), and PrRP acts synergistically with NE to activate CRH neurons and the HPA axis (Maruyama et al, 2001; Seal et al, 2002; Uchida et al, 2010). Lesions that decrease NA input to the mpPVN markedly attenuate CRH neuronal cFos activation responses to interoceptive signals (Li et al, 1996; Fraley and Ritter, 2003; Rinaman, 2003a; Ritter et al, 2003; Rinaman and Dzmura, 2007; Schiltz and Sawchenko, 2007; Bienkowski and Rinaman, 2008). Central administration of PrRP or GLP-1 activates cFos in the large majority of CRH-positive mpPVN neurons, and also increases plasma levels of corticosterone (Turton et al, 1996; Rowland et al, 1997; Kinzig et al, 2003; Mera et al, 2006).…”

Delineating v-Src downstream effector pathways in transformed myoblasts

“…An alternative hypothesis sees oncoprotein host dependency deriving from a requirement for activation of multiple downstream pathways. In some cell species, certain pathways may be constitutively active and thus activation of a single pathway will be sufficient for transformation; in other cell contexts, multiple pathways have to be activated for transformation (Li et al, 1996). Hostdependent differences concerning the role of the RasRaf-MAPK kinase (MEK) pathway in v-Src-induced transformation have also been reported.…”

“…A long-standing issue concerning transformation by retroviral oncogenes is host dependency, attributed to differences in oncoprotein expression levels and/or activity, or to specific factors whose expression varies in different cell types or species (Verderame et al, 1989;Falcone et al, 1992;Li et al, 1996). An alternative hypothesis sees oncoprotein host dependency deriving from a requirement for activation of multiple downstream pathways.…”

Chicken embryonic stem cells as a non‐mammalian embryonic stem cell model

“…Such genes, as well as specific chicken genes, cSox2, cMyc and a chicken Klf gene, could serve as a molecular basis for such experiments. Interestingly, the c-Myc gene is a well-known factor in the avian field as the v-Myc oncogene was identified in the MC29, a natural avian retrovirus and the transformation potential of the different c-Myc and v-Myc forms were described in great detail (Farina et al 1992;Li et al 1996). In regard to papers demonstrating a somatic reprogrammation without the use of the active proto-oncogene c-Myc (Nakagawa et al 2008), even if the process appears to be more difficult, it would be highly informative to compare the presence or the absence of the different Myc genes (c-Myc, N-Myc and L-Myc) from both avian and mammalian origin during the reprogramming process.…”