scholarly journals Behavioral evolution drives hindbrain diversification among Lake Malawi cichlid fish

2018 ◽  
Author(s):  
Ryan A. York ◽  
Allie Byrne ◽  
Kawther Abdhilleh ◽  
Chinar Patil ◽  
J. Todd Streelman ◽  
...  
Keyword(s):  
Courtship Behavior ◽  
Cichlid Fish ◽  
Brain Evolution ◽  
Brain Structures ◽  
Lake Malawi ◽  
Early Gene ◽  
Evolutionary Diversification ◽  
Evolutionary Changes ◽  
And Function ◽  
Mosaic Brain Evolution

AbstractThe evolutionary diversification of animal behavior is often associated with changes in the structure and function of nervous systems. Such evolutionary changes arise either through alterations of individual neural components (“mosaically”) or through scaling of the whole brain (“conceitedly”). Here we show that the evolution of a specific courtship behavior in Malawi cichlid fish, the construction of mating nests known as bowers, is associated with rapid, extensive, and specific diversification of orosensory, gustatory centers in the hindbrain. We find that hindbrain volume varies significantly between species that build pit (depression) compared to castle (mound) type bowers and that hindbrain features evolve rapidly and independently of phylogeny among castle-building species. Using immediate early gene expression, we confirmed a functional role for hindbrain structures during bower building. Comparisons of bower building species in neighboring Lake Tanganyika show patterns of neural diversification parallel to those in Lake Malawi. Our results suggest that mosaic brain evolution via alterations to individual brain structures is more extensive and predictable than previously appreciated.

scholarly journals Behavioral evolution contributes to hindbrain diversification among Lake Malawi cichlid fish

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ryan A. York ◽  
Allie Byrne ◽  
Kawther Abdilleh ◽  
Chinar Patil ◽  
Todd Streelman ◽  
...  
Keyword(s):  
Courtship Behavior ◽  
Cichlid Fish ◽  
Brain Evolution ◽  
Brain Structures ◽  
Lake Malawi ◽  
Early Gene ◽  
Evolutionary Diversification ◽  
Evolutionary Changes ◽  
And Function ◽  
Mosaic Brain Evolution

AbstractThe evolutionary diversification of animal behavior is often associated with changes in the structure and function of nervous systems. Such evolutionary changes arise either through alterations of individual neural components (“mosaically”) or through scaling of the whole brain (“concertedly”). Here we show that the evolution of a courtship behavior in Malawi cichlid fish is associated with rapid, extensive, and specific diversification of orosensory, gustatory centers in the hindbrain. We find that hindbrain volume varies significantly between species that build pit (depression) compared to castle (mound) type bowers and that this trait is evolving rapidly among castle-building species. Molecular analyses of neural activity via immediate early gene expression indicate a functional role for hindbrain structures during bower building. Finally, comparisons of bower building species in neighboring Lake Tanganyika suggest parallel patterns of neural diversification to those in Lake Malawi. Our results suggest that mosaic brain evolution via alterations to individual brain structures is more extensive and predictable than previously appreciated.

The coordinated structure of mosaic brain evolution

2001 ◽  
Vol 24 (2) ◽  
pp. 281-282 ◽  
Author(s):  
Robert A. Barton
Keyword(s):  
Brain Evolution ◽  
Brain Structures ◽  
Evolutionary Change ◽  
Evolution Model ◽  
Developmental Constraints ◽  
Mosaic Evolution ◽  
Set Up ◽  
Mosaic Brain Evolution

The opposition set up between co-ordinated and mosaic brain evolution distracts from the fact that the two go hand-in-hand. Here and elsewhere (Barton & Harvey 2000), I show that the patterns of co- ordinated evolutionary change among brain structures fit a mosaic evolution model. The concept of overarching developmental constraints is unnecessary and is not supported by the data.

scholarly journals Structural and functional brain asymmetries in the early phases of life: a scoping review

2021 ◽  
Author(s):  
Patrizia Bisiacchi ◽  
Elisa Cainelli
Keyword(s):  
Scoping Review ◽  
Right Hemisphere ◽  
Final Analysis ◽  
Brain Structures ◽  
Large Variability ◽  
Speech Stimuli ◽  
Morphological Asymmetry ◽  
Cerebral Asymmetries ◽  
The Right ◽  
And Function

AbstractAsymmetry characterizes the brain in both structure and function. Anatomical asymmetries explain only a fraction of functional variability in lateralization, with structural and functional asymmetries developing at different periods of life and in different ways. In this work, we perform a scoping review of the cerebral asymmetries in the first brain development phases. We included all English-written studies providing direct evidence of hemispheric asymmetries in full-term neonates, foetuses, and premature infants, both at term post-conception and before. The final analysis included 57 studies. The reviewed literature shows large variability in the used techniques and methodological procedures. Most structural studies investigated the temporal lobe, showing a temporal planum more pronounced on the left than on the right (although not all data agree), a morphological asymmetry already present from the 29th week of gestation. Other brain structures have been poorly investigated, and the results are even more discordant. Unlike data on structural asymmetries, functional data agree with each other, identifying a leftward dominance for speech stimuli and an overall dominance of the right hemisphere in all other functional conditions. This generalized dominance of the right hemisphere for all conditions (except linguistic stimuli) is in line with theories stating that the right hemisphere develops earlier and that its development is less subject to external influences because it sustains functions necessary to survive.

Sex Steroids and Human Behavior: Implications for Developmental Psychopathology

CNS Spectrums ◽  
2001 ◽  
Vol 6 (1) ◽  
pp. 75-88 ◽  
Author(s):  
Gerianne M. Alexander ◽  
Bradley S. Peterson
Keyword(s):  
Sex Differences ◽  
Human Behavior ◽  
Sex Steroids ◽  
Developmental Psychopathology ◽  
Mammalian Species ◽  
Brain Structures ◽  
Postnatal Life ◽  
Brain Structure And Function ◽  
Atypical Development ◽  
And Function

AbstractIn a variety of mammalian species, prenatal androgens organize brain structures and functions that are later activated by steroid hormones in postnatal life. In humans, studies of individuals with typical and atypical development suggest that sex differences in reproductive and nonreproductive behavior derive in part from similar prenatal and postnatal steroid effects on brain development. This paper provides a summary of research investigating hormonal influences on human behavior and describes how sex differences in the prevalences and natural histories of developmental psychopathologies may be consistent with these steroid effects. An association between patterns of sexual differentiation and specific forms of psychopathology suggests novel avenues for assessing the effects of sex steroids on brain structure and function, which may in turn improve our understanding of typical and atypical development in women and men.

scholarly journals Cell-specific expression and individual function of prohormone convertase PC1/3 in Tribolium larval growth highlights major evolutionary changes between beetle and fly neuroendocrine systems

EvoDevo ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sonja Fritzsche ◽  
Vera S. Hunnekuhl
Keyword(s):  
Larval Growth ◽  
Neuroendocrine System ◽  
Small Subset ◽  
Specific Cell ◽  
Specific Expression ◽  
Individual Function ◽  
Evolutionary Changes ◽  
Cell Groups ◽  
Cell Type Specific Expression ◽  
And Function

Abstract Background The insect neuroendocrine system acts in the regulation of physiology, development and growth. Molecular evolution of this system hence has the potential to allow for major biological differences between insect groups. Two prohormone convertases, PC1/3 and PC2, are found in animals and both function in the processing of neuropeptide precursors in the vertebrate neurosecretory pathway. Whereas PC2-function is conserved between the fly Drosophila and vertebrates, ancestral PC1/3 was lost in the fly lineage and has not been functionally studied in any protostome. Results In order to understand its original functions and the changes accompanying the gene loss in the fly, we investigated PC1/3 and PC2 expression and function in the beetle Tribolium castaneum. We found that PC2 is broadly expressed in the nervous system, whereas surprisingly, PC1/3 expression is restricted to specific cell groups in the posterior brain and suboesophageal ganglion. Both proteases have parallel but non-redundant functions in adult beetles’ viability and fertility. Female infertility following RNAi is caused by a failure to deposit sufficient yolk to the developing oocytes. Larval RNAi against PC2 produced moulting defects where the larvae were not able to shed their old cuticle. This ecdysis phenotype was also observed in a small subset of PC1/3 knockdown larvae and was strongest in a double knockdown. Unexpectedly, most PC1/3-RNAi larvae showed strongly reduced growth, but went through larval moults despite minimal to zero weight gain. Conclusions The cell type-specific expression of PC1/3 and its essential requirement for larval growth highlight the important role of this gene within the insect neuroendocrine system. Genomic conservation in most insect groups suggests that it has a comparable individual function in other insects as well, which has been replaced by alternative mechanisms in flies.

scholarly journals Flexible annotation atlas of the mouse brain: combining and dividing brain structures of the Allen Brain Atlas while maintaining anatomical hierarchy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Norio Takata ◽  
Nobuhiko Sato ◽  
Yuji Komaki ◽  
Hideyuki Okano ◽  
Kenji F. Tanaka
Keyword(s):  
Mouse Brain ◽  
Brain Structures ◽  
Brain Atlas ◽  
Resting State Functional Connectivity ◽  
Brain Science ◽  
Step Procedure ◽  
Public Resources ◽  
Large Brain ◽  
Magnetic Resonance Imaging Mri ◽  
And Function

AbstractA brain atlas is necessary for analyzing structure and function in neuroimaging research. Although various annotation volumes (AVs) for the mouse brain have been proposed, it is common in magnetic resonance imaging (MRI) of the mouse brain that regions-of-interest (ROIs) for brain structures (nodes) are created arbitrarily according to each researcher’s necessity, leading to inconsistent ROIs among studies. One reason for such a situation is the fact that earlier AVs were fixed, i.e. combination and division of nodes were not implemented. This report presents a pipeline for constructing a flexible annotation atlas (FAA) of the mouse brain by leveraging public resources of the Allen Institute for Brain Science on brain structure, gene expression, and axonal projection. A mere two-step procedure with user-specified, text-based information and Python codes constructs FAA with nodes which can be combined or divided objectively while maintaining anatomical hierarchy of brain structures. Four FAAs with total node count of 4, 101, 866, and 1381 were demonstrated. Unique characteristics of FAA realized analysis of resting-state functional connectivity (FC) across the anatomical hierarchy and among cortical layers, which were thin but large brain structures. FAA can improve the consistency of whole brain ROI definition among laboratories by fulfilling various requests from researchers with its flexibility and reproducibility.

scuteexpression inCalliphora vicinareveals an ancestral pattern of longitudinal stripes on the thorax of higher Diptera

Development ◽  
2002 ◽  
Vol 129 (3) ◽  
pp. 563-572 ◽  
Author(s):  
Daniela Pistillo ◽  
Nick Skaer ◽  
Pat Simpson
Keyword(s):  
Expression Pattern ◽  
Regulatory Elements ◽  
Calliphora Vicina ◽  
Transcriptional Activators ◽  
Gene Complex ◽  
Secondary Loss ◽  
Evolutionary Changes ◽  
Sensory Bristles ◽  
And Function ◽  
Bristle Patterns

In Drosophila the stereotyped arrangement of sensory bristles on the notum is determined by the tightly regulated control of transcription of the achaete-scute (ac-sc) genes which are expressed in small proneural clusters of cells at the sites of each future bristle. Expression relies on a series of discrete cis-regulatory elements present in the ac-sc gene complex that are the target of the transcriptional activators pannier (pnr) and the genes of the iroquois complex. Stereotyped bristle patterns are common among species of acalyptrate Schizophora such as Drosophila, and are thought to have derived from an ancestral pattern of four longitudinal rows extending the length of the scutum, through secondary loss of bristles. To investigate evolutionary changes in bristle patterns and ac-sc regulation by pnr, we have isolated homologues of these genes from Calliphora vicina, a species of calyptrate Schizophora separated from Drosophila by at least 100 million years. Calliphora vicina displays a pattern of four rows of bristles on the scutum resembling the postulated ancestral one. We find that sc in Calliphora is expressed in two longitudinal stripes on the medial scutum that prefigure the development of the rows of acrostichal and dorsocentral bristles. This result suggests that a stripe-like expression pattern of sc may be an ancestral feature and may have preceded the evolution of proneural clusters. The implications for the evolution of the cis-regulatory elements responsible for sc expression in the proneural clusters of Drosophila, and function of Pnr are discussed.

scholarly journals Maternal investment, life histories and the evolution of brain structure in primates

2019 ◽  
Vol 286 (1911) ◽  
pp. 20191608 ◽  
Author(s):  
Lauren E. Powell ◽  
Robert A. Barton ◽  
Sally E. Street
Keyword(s):  
Life History ◽  
Life Histories ◽  
Brain Size ◽  
Developmental Trajectories ◽  
Adult Life ◽  
Maternal Investment ◽  
Brain Evolution ◽  
Brain Structures ◽  
Juvenile Period ◽  
Adult Lifespan

Life history is a robust correlate of relative brain size: larger-brained mammals and birds have slower life histories and longer lifespans than smaller-brained species. The cognitive buffer hypothesis (CBH) proposes an adaptive explanation for this relationship: large brains may permit greater behavioural flexibility and thereby buffer the animal from unpredictable environmental challenges, allowing for reduced mortality and increased lifespan. By contrast, the developmental costs hypothesis (DCH) suggests that life-history correlates of brain size reflect the extension of maturational processes needed to accommodate the evolution of large brains, predicting correlations with pre-adult life-history phases. Here, we test novel predictions of the hypotheses in primates applied to the neocortex and cerebellum, two major brain structures with distinct developmental trajectories. While neocortical growth is allocated primarily to pre-natal development, the cerebellum exhibits relatively substantial post-natal growth. Consistent with the DCH, neocortical expansion is related primarily to extended gestation while cerebellar expansion to extended post-natal development, particularly the juvenile period. Contrary to the CBH, adult lifespan explains relatively little variance in the whole brain or neocortex volume once pre-adult life-history phases are accounted for. Only the cerebellum shows a relationship with lifespan after accounting for developmental periods. Our results substantiate and elaborate on the role of maternal investment and offspring development in brain evolution, suggest that brain components can evolve partly independently through modifications of distinct developmental phases, and imply that environmental input during post-natal maturation may be particularly crucial for the development of cerebellar function. They also suggest that relatively extended post-natal maturation times provide a developmental mechanism for the marked expansion of the cerebellum in the apes.

scholarly journals The Structure and Function of the DNA from Bacteriophage Lambda

1966 ◽  
Vol 49 (6) ◽  
pp. 29-57 ◽  
Author(s):  
David S. Hogness
Keyword(s):  
Early Gene ◽  
Second Step ◽  
Wild Type ◽  
Gene Orientation ◽  
Variant Gene ◽  
Position And Orientation ◽  
The Right ◽  
And Function ◽  
Lambda Dna

The position and orientation of genes in lambda and lambda dg DNA are described. The position of six genes located in the right half of isolated lambda DNA was found to be -(N, iλ)--O-P---Q-R-(right end of DNA), which is their order on the genetic map of the vegetative phage. The order of the three genes of the galactose operon (k, t, and e) located in the left half of lambda dg DNA was found to be (left end of DNA)----k-t-e-, consistent with Campbell's model (5) for the formation of this variant. Gene orientation, defined as the direction of transcription along the DNA, is inferred to be from right to left for the galactose operon in lambda dg DNA. The strand of lambda DNA which functions as template in transcription of N, an "early" gene required for normal replication of lambda DNA, was determined as a first step in ascertaining the orientation of this gene. The method includes isolation of each strand, formation of each of two heteroduplex molecules consisting of one strand from wild-type and one from an N mutant) and comparison of their N activities. The second step, which consists of ascertaining the 5'-to-3' direction of each strand, is discussed, as is a determination of the orientation of gene R.

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