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Sacha inchi (Plukenetia volubilisL.) is known to naturally grow under a wide range of elevational gradients in South America. We assessed the combined effects of altitude (560, 900, 1200, and 1490 m asl) and season on leaf‐ and whole‐plant traits and seed chemicals of sacha inchi plants in Xishuangbanna, Southwest China, to explore the optimum altitudinal zone for its cultivation. Leaf maximum net photosynthetic rate (Amax), stomatal conductance (gs), and dark respiration (Rd) were greatest in the wet season and lowest in the cool season. With similar values in the wet season between altitudes, the reduction in Amaxand gswas greater in plants growing in higher elevations than in lower elevations in the cool season. Plant biomass and fruit production were highest at lower altitudes and dramatically decreased above 900 m, which can primarily be attributed to a C source limitation. Sacha inchi could be useful for cropping in cooler regions because the reproductive growth is adapted to high elevations. The oil and protein content and linolenic and unsaturated fatty acid (UFA) concentrations in seeds were highest in the cool season. With an increase in elevation, the linolenic and UFA concentrations in seeds increased. We concluded that lower altitudes (<900 m) could be the optimum zone for growth and yield of sacha inchi plants whereas seeds collected from plants growing at higher altitudes (>900 m) and in the cool season appear to have better quality.

This study investigated the influence of expression of proteins of the INK4 family, particularly p16, on the growth and self-renewal kinetics of hematopoietic cells. First, retrovirus-mediated gene transfer (RMGT) was used to restore p16INK4aexpression in the p16INK4a-deficient lymphoid and myeloid cell lines BV173 and K562, and it was confirmed that this inhibited their growth. Second, to sequester p16INK4a and related INK4 proteins, cyclin-dependent kinase 4 (CDK4) was retrovirally transduced into normal human CD34+ bone marrow cells and then cultured in myeloid colony-forming cell (CFC) assays. The growth of CDK4-transduced colonies was more rapid; the cell-doubling time was reduced; and, upon replating, the colonies produced greater yields of secondary colonies than mock-untransduced controls. Third, colony formation was compared by marrow cells fromp16INK4a−/− mice and wild-type mice. The results from p16INK4a−/−marrow were similar to those from CDK4-transduced human CFCs, in terms of growth rate and replating ability, and were partially reversed by RMGT ofp16INK4a. Lines of immature granulocytic cells were raised from 15 individual colonies grown from the marrow ofp16INK4a−/−mice. These had a high colony-forming ability (15%) and replating efficiency (96.7%). The p16INK4a−/−cell lines readily became growth factor–independent upon cytokine deprivation. Taken together, these results demonstrate that loss of INK4 proteins, in particular p16INK4a, increases the growth rate of myeloid colonies in vitro and, more importantly, confers an increased ability for clonal expansion on hematopoietic progenitor cells.

This study investigated the influence of expression of proteins of the INK4 family, particularly p16, on the growth and self-renewal kinetics of hematopoietic cells. First, retrovirus-mediated gene transfer (RMGT) was used to restore p16INK4aexpression in the p16INK4a-deficient lymphoid and myeloid cell lines BV173 and K562, and it was confirmed that this inhibited their growth. Second, to sequester p16INK4aand related INK4 proteins, cyclin-dependent kinase 4 (CDK4) was retrovirally transduced into normal human CD34+bone marrow cells and then cultured in myeloid colony-forming cell (CFC) assays. The growth of CDK4-transduced colonies was more rapid; the cell-doubling time was reduced; and, upon replating, the colonies produced greater yields of secondary colonies than mock-untransduced controls. Third, colony formation was compared by marrow cells fromp16INK4a−/−mice and wild-type mice. The results from p16INK4a−/−marrow were similar to those from CDK4-transduced human CFCs, in terms of growth rate and replating ability, and were partially reversed by RMGT ofp16INK4a. Lines of immature granulocytic cells were raised from 15 individual colonies grown from the marrow ofp16INK4a−/−mice. These had a high colony-forming ability (15%) and replating efficiency (96.7%). The p16INK4a−/−cell lines readily became growth factor–independent upon cytokine deprivation. Taken together, these results demonstrate that loss of INK4 proteins, in particular p16INK4a, increases the growth rate of myeloid colonies in vitro and, more importantly, confers an increased ability for clonal expansion on hematopoietic progenitor cells.