Developmental Variations

Another way to show that plants are actively metabolizing alkaloids is by determining the fluctuations that occur during a single day. In essence, this is catabolism of alkaloids with metabolites unknown. 

In the late 1950s and early 1960s several papers appeared which documented the decrease of alkaloid content during plant development. Sometimes periodic variations (increases or decreases) were also observed. Modem separation and assay methods made these experiments possible. 

1959 cannot be produced from the y-coniceine that disappears concurrently, unless it appears that additional y-coniceine is synthesized at a very rapid rate and then converted into coniine (see Section 6.9.1). 

On the other hand, the role of perloline in Festuca arundinacea (tall fescue) is quite different, because it shows almost a fourfold increase during 

Change of an alkaloid spectrum in a plant organ during its development often indicates at least one phenomenon de novo synthesis, translocation, and degradation (e.g., tabersonine and the pair dehydroaspidospermidine-vincadifformine on page 217). 

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Figure 2. Temporal profile of DDC enzyme activity during Drosophila development. Note the major peaks of DDC induction during late embryo-genesis, at pupariation, and at the time of eclosion of the adult from the pupal case. At these developmental times when there is extensive synthesis and hardening of cuticle, the induced DDC in the hypoderm is involved in this process. Levels of DDC in the CNS show much less developmental variation (Hirsh, 1986). Figure adapted from Hirsh, 1986.

There is no reason to think that the other kind of hypothetical module, the kind exemplified by the rape module that directs different responses to different situations, will be any less susceptible to developmental variation than quasi-deterministic modules such as the homosexuality module. Plus, for that matter, there is no particular reason to suppose that there will be less initial genetic variability in cases such as the rape module. So perhaps the perspectives of evolutionary psychology and behavioural genetics should not be seen as fundamentally disparate. 

VOIRIN, B., BAYET, C., Developmental variations in leaf flavonoid aglycones of Mentha x piperita, Phytochemistry, 1992, 31,2299-2304. 

Oral administration of 3 mg uranium/ %/day as uranyl acetate dihydrate to pregnant mice on gestation days 6-15 caused an increase in fetotoxicity (stunted fetuses, external and skeletal malformations, and developmental variations) and maternal toxicity." In reproductive studies, no adverse effects were observed in testicular function or spermatogenesis in male mice treated with up to 80mg/kg/day uranyl acetate dihydrate for 64 days."... 

As mentioned in the introduction, Khera hypothesized that unspeciflc maternal toxicity, per se, was significanfly associated with various fetal adverse effects, including major malformations (5, 6). Based on retrospective analysis of literature data in rodents, hamster, and rabbits he proposed that a number of effects on the offspring occurred merely as a consequence of maternally mediated toxicity. Proposed maternal toxicity-related effects included decreased fetal body weight, external/visceral and skeletal malformations and developmental variations, and resorptions. Examples of the malformations Khera associated with maternal toxicity include exencephaly, open eye, and fused thoracic or lumbar vertebrae in mice, and fused ribs, exencephaly, and eye defects in hamsters, as well as rib, vertebral, and sternebral defects in rats and rabbits. Khera s hypothesis was that such effects were species-specific, and were seldom observed at dosages below those that were maternally toxic. 

Biel M, Zong X, Ludwig A, Sautter A, Hofmann F (1999) Structure and function of cyclic nucleotide-gated channels. Rev Physiol Biochem Pharmacol 135 151-71 Blackshaw S, Eliasson MJ, Sawa A, Watkins CC, Krug D, Gupta A, Arai T, et al. (2003) Species, strain and developmental variations in hippocampal neuronal and endothelial nitric oxide synthase clarify discrepancies in nitric oxide-dependent synaptic plasticity. Neuroscience 119 979-90... 

Chen H, Cabon E, Sun P, Parmantier E, Dupouey P, Jacque C, Zalc B (1993) Regional and developmental variations of GEAP and actin ruRNA levels in the CNS of jimpy and shiverer mutant mice. J Mol Neurosci 4 89-96. 

Evolution by natural selection requires variation, differences between cells, organ function, individuals, or groups. Many important phenotypic variations of the human brain are developmental variations. The variation required by natural selection operating during prenatal development occurs primarily as a result of random and nonrandom local environmental effects on gene expression. The importance of this for our context is that it tells us the idea that fetal development is malleable by circumstance is expected from what we already know about the evolution of development. 

Thiodtcarb Not established (females 13-49) 10 300 Decreased fetal body weight and increased number of litters and fetuses wuth developmental variations Rat Developmental 0,033... 

As a consequence, developmental variations in the metabolic fate of drugs can occur and are apparent for many phase I (primarily oxidation, cytochrome P450) and phase II (conjugation) enzymes. 

DEVELOPMENTAL VARIATION IN ASPARTATE-FAMILY AMINO ACID BIOSYNTHESIS BY ISOLATED CHLOROPLASTS... 

When conducting developmental studies with isolated chloroplasts, it is difficult to find an appropriate index for comparison. For cample, rates of CO2 photoassimilation and photosynthetic O2 evolution have traditionally been expressed on a chlorophyll basis (micromole/mg chl/hr) yet, it is well known that as leaf tissues mature, the amount of chlorophyll per plastid increases several fold [9]. Thus, one might get a flawed view of developmental variation in synthetic activity utilizing chlorophyll as the sole ind However, this does not appear to be the case here since a similar pattern was observed regardless of whether chlorophyll, protein or plastid number was used as the basis of comparison (Table 1). 

The basis for this variation in amino add formation in isolated chloroplasts is not yet clear. However, there are several factors which could influence synthesis, including 1) developmental variation in photosynthetic activity, 2) changes in chloroplast envelope permeability and 3) fluctuations in the activity of key regulatory en mes. 

Developmental Variation in Aspartate-Family Amino Acid Biosynthesis by Isolated... 

Sena E (1966) Developmental variation of alkaline phosphatase in D. melanogaster. M S Thesis. Cornell Univ Ithaca, New York Serebrovsky AS (1938) Dokl Acad Sci USSR (Russ) 19 77-78 Serebrovsky AS, Dubinin NP (1929) Adv Exp Biol (Russ) 4 235-247 Serfling E, Panitz R, Wobus U (1969) Chromosoma 28 107-119 Serov OL (1968) Genetica (Russ) 4 135-145 Serov OL, Chlebodarova JN (1973) Genetica (Russ) 9 45-48 Serov OL, Korochkin LI (1971) Ontogenes (Russ) 2 471-478... 

M. C. Field, A. K. Menon G. A. Cross. Developmental variation of glycosylphosphatidylinositol membrane anchors in Trypanosoma brucei. Identification of a candidate biosynthetic precursor of the glycosylphosphatidylinositol anchor of the major procyclic stage surface glycoprotein. J Biol Chem, 1991, 266, 8392-8400. 

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