TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: Protein kinase D (PKD or PKD1) is a serine/threonine protein kinase that has been shown to play a role in a variety of cellular processes; however, the function of PKD1 in the skin has not been fully investigated. The balance between proliferation and differentiation processes in the predominant cells of the epidermis, the keratinocytes, is essential for normal skin function.', 'To investigate the effect of PKD1 deficiency on proliferation and differentiation of epidermal keratinocytes.', 'We utilized a floxed PKD1 mouse model such that infecting epidermal keratinocytes derived from these mice with an adenovirus expressing Cre-recombinase allowed us to determine the effect of PKD1 gene loss in vitro. Proliferation and differentiation were monitored using qRT-PCR, Western blot, transglutaminase activity assays, [3H]thymidine incorporation into DNA and cell cycle analysis.', 'A significant decrease in PKD1 mRNA and protein levels was achieved in adenoviral Cre-recombinase-infected cells. Deficiency of PKD1 resulted in significant increases in the mRNA and protein expression of various differentiation markers such as loricrin, involucrin, and keratin 10 either basally and/or upon stimulation of differentiation. PKD1-deficient keratinocytes also showed an increase in transglutaminase expression and activity, indicating an anti-differentiative role of PKD1. Furthermore, the PKD1-deficient keratinocytes exhibited decreased proliferation. However, PKD1 loss had no effect on stem cell marker expression.\Question: Does protein kinase D1 deficiency promote differentiation in epidermal keratinocytes?

SOLUTION: Cre-recombinase-mediated knockdown represents an additional approach demonstrating that PKD1 is an anti-differentiative, pro-proliferative signal in mouse keratinocytes.

PROBLEM: Context: The present analyses intend to clarify if gender and puberty modify the relationship between bone development (modeling and remodeling) and fat mass at the forearm.', 'Data were collected from participants (139 males, 157 females, age = 5-19 years) of the Dortmund Nutritional and Anthropometric Longitudinally Designed study in a cross-sectional investigation. The main outcome measures were total and trabecular bone mineral density (BMDtot and BMDtrab), strength strain index (SSI) and parameters associated with modeling (cortical area, CA; periosteal circumference, CP) and remodeling (cortical bone mineral density, BMDcort, endosteal circumference, CE) were analyzed in their relationship to cross-sectional fat (FA) and muscle area (MA) at the forearm.', 'BMDtot was correlated with FA in pubertal males (r = -0.25). BMDtrab was contrarily predicted by FA in pubertal males and females (r = -0.28 vs. 0.31). FA was correlated with BMDcort (r = -0.32) and CE (r = 0.26) in pubertal females. MA was positively correlated with CA, CP and SSI.\Question: Is local body composition associated with gender differences of bone development at the forearm in puberty?

SOLUTION: Modeling and bone strength were primarily predicted by MA. Markers of remodeling were positively correlated with FA in pubertal females, but not in prepubertal individuals and pubertal males. Therefore, gender and puberty modify the relationship between FA and bone development.

PROBLEM: Context: The interactions among experience, emotion, and memory are considered to be instrumental in the ontogeny and maintenance of acquired emotional and behavioral disorders (e.g., phobias). Here we address the question whether an anxiety-like state can associate with taste to produce conditioned taste aversion (CTA).', 'We have used an anxiogenic agent, the 5-HT2C receptor agonist meta-chlorophenylpiperazine (mCPP), to induce an anxiety-like emotional state in rats after consumption of an unfamiliar tastant.', 'The anxiogenic agent induced CTA. The mCPP-induced CTA could be prevented by concomitant administration of ethanol, which is known to reverse mCPP-induced anxiety-like behavior, at a concentration that had no effect on CTA memory. In contrast, ethanol did not prevent LiCl-induced CTA. Administration of mCPP before the consumption of the tastant had no effect on the preference for that tastant.\Question: Does anxiety-like state associate with taste to produce conditioned taste aversion?

SOLUTION:
Taken together, these results indicate that anxiety-like state can serve as the unconditioned stimulus in CTA training. This finding may be relevant to the ontogeny of pathologies involving food aversion.