Comparison Of Growth Rates Research Articles

Regulation of the Development of Human Neurons by Substratum Elasticity

Growth cones, the sensory tips of developing axons, respond to molecular cues present in the environment. Additionally, recent studies suggest local differences in environmental rigidity affect axon development via mechanosensitive protein regulation in growth cones, and is dependent upon neuronal subtype. Neurites innervating the Central Nervous System (CNS) grow more rapidly on flexible substrata. Conversely, neurites projecting into the Peripheral Nervous System (PNS) prefer rigid substrata. By using human forebrain (hFBs) and motor neurons (hMNs) differentiated from Induced Pluripotent Stem Cells (IPSCs), we compared growth rates and morphology of CNS and PNS neurons on varying substrata stiffnesses. We found MNs prefer more rigid substrata, while forebrain neurons do not have a strong preference for rigidity. Finally, we found both hFBs and hMNs express mechanosensitive ion channels. Future studies should investigate differential expression patterns of these ion channels on different rigidities as a possible mechanism for the differential growth we observed.Support or Funding InformationNIH RO1NS41564‐10 (to T.M.G)NIH T32GM007507 (to UW‐NTP)IBS‐SRP at UW‐Madison (NSF grant NSF‐DBI 1063085)NIH‐NIGMS R25GM096955 (to Edu B. Suarez‐Martinez)

Mediterranean, invasive, woody species grow larger than their less-invasive counterparts under potential global environmental change.

Revealing biological differences between invasive and noninvasive species is essential for predicting species' distribution changes with global environmental change. While most research has focused on differences between invasive and noninvasive species under favorable conditions using herbaceous species, invasive woody angiosperms are also of great ecological concern. Our study focused on how growth and allocation may change for invasive and noninvasive, mediterranean, woody angiosperms under future conditions caused by global change, specifically increased nitrogen deposition and drought. We tested how seedling functional traits differed between invasive and noninvasive woody angiosperms under different experimental conditions in a greenhouse setting. We compared growth rates and allocation patterns using two levels of soil nitrogen and three levels of watering. We also examined trait log response ratios to increases in nitrogen and increases in water. Our study sampled angiosperm trees and shrubs, incorporating congeneric/confamilial relationships through 13 phylogenetically controlled contrasts. Three functional traits were highly and positively associated with plant invasiveness for most conditions studied: seedling plant mass, leaf area, and height. Invasive species also had significantly higher root mass ratios at low water regardless of nitrogen input. Invasive and noninvasive species had similar log response ratios to increases in nitrogen and watering for studied traits. Mediterranean, woody, invasive species' larger mass, leaf area, and early height advantage under elevated nitrogen input and increased root production in drought conditions may lead to increased invasion of these species with expected global climate change.

NGT-3D: a simple nematode cultivation system to study Caenorhabditis elegans biology in 3D.

ABSTRACTThe nematode Caenorhabditis elegans is one of the premier experimental model organisms today. In the laboratory, they display characteristic development, fertility, and behaviors in a two dimensional habitat. In nature, however, C. elegans is found in three dimensional environments such as rotting fruit. To investigate the biology of C. elegans in a 3D controlled environment we designed a nematode cultivation habitat which we term the nematode growth tube or NGT-3D. NGT-3D allows for the growth of both nematodes and the bacteria they consume. Worms show comparable rates of growth, reproduction and lifespan when bacterial colonies in the 3D matrix are abundant. However, when bacteria are sparse, growth and brood size fail to reach levels observed in standard 2D plates. Using NGT-3D we observe drastic deficits in fertility in a sensory mutant in 3D compared to 2D, and this defect was likely due to an inability to locate bacteria. Overall, NGT-3D will sharpen our understanding of nematode biology and allow scientists to investigate questions of nematode ecology and evolutionary fitness in the laboratory.

Three-dimensional microtissues essentially contribute to preclinical validations of therapeutic targets in breast cancer.

A 3D microtissues using T47D and JIMT‐1 cells were generated to analyze tissue‐like response of breast cancer cells after combined human epidermal growth factor receptor 2 (HER2)‐targeted treatment and radiation. Following lentiviral knockdown of HER2, we compared growth rate alterations using 2D monolayers, 3D microtissues, and mouse xenografts. Additionally, to model combined therapeutic strategies, we treated HER2‐depleted T47D cells and 3D microtissues using trastuzumab (anti‐HER2 antibody) in combination with irradiation. Comparison of HER2 knockdown with corresponding controls revealed growth impairment due to HER2 knockdown in T47D 2D monolayers, 3D microtissues, and xenografts (after 2, 12, and ≥40 days, respectively). In contrast, HER2 knockdown was less effective in inhibiting growth of trastuzumab‐resistant JIMT‐1 cells in vitro and in vivo. Combined administration of trastuzumab and radiation treatment was also analyzed using T47D 3D microtissues. Administration of both, radiation (5 Gy) and trastuzumab, significantly enhanced the growth inhibiting effect in 3D microtissues. To improve the predictive power of potential drugs—as single agents or in combination—here, we show that regarding tumor growth analyses, 3D microtissues are highly comparable to outcomes derived from xenografts. Considering increased limitations for animal experiments on the one hand and strong need of novel drugs on the other hand, it is indispensable to include highly reproducible 3D microtissue platform in preclinical analyses to validate more accurately the capacity of future drug‐combined radiotherapy.

Bone histology of the giant fossil dormouse Hypnomys onicensis (Gliridae, Rodentia) from Balearic Islands

Insular gigantism is frequent in fossil and extant micromammals. It is widely assumed to result from increased food availability through expanded dietary niches under decreased interspecific competition. We compared the bone histology of the fossil giant dormouse Hypnomys onycensis (Gliridae) from the Balearic Islands with that of its closest living relative, Eliomys quercinus. Both display the same bone tissue types at similar ontogenetic stages, indicating comparable growth rates. Skeletochronological analysis shows that Hypnomys had an exceptionally long lifespan. Gigantism in insular Hypnomys hence results from a shift in life history toward the slow end of the slow–fast continuum.

Evaluation of Smoked Skipjack Processing Byproduct Meal as an Alternative Feed Ingredient for Juvenile Humpback Grouper Cromileptes altivelis

This study aimed to evaluate the utilization of smoked skipjack processing byproduct meal (SPBM) to reduce the use of fish meal (FM) for juvenile humpback grouper Cromileptes altivelis. This study consisted of digestibility test of SPBM and biological test to observe growth performance. Five isonitrogenous and isocaloric experimental diets were used: Diet A contains 0% SPBM as a control diet, and diets B, C, D, and E contain 25%, 50%, 75%, and 100% of SPBM protein to substitute FM, respectively. Digestibility trial was performed for 14 days by adding Cr2O3 into the experimental diets and collecting fecal matter 40–60 minutes after each feeding. For growth trial, juvenile humpback grouper were kept in glass aquariums and fed by the experimental diet until apparent satiation for 60 days. Our result shows that the dry matter and protein SPBM apparent digestibility coefficient is lower compared to FM. The fish that was fed with diet B and C performed a comparable specific growth rate, feed efficiency, and protein retention compared to control (p > 0.05). However, lower specific growth rate, feeding efficiency, and protein retention were observed in fish that was fed with diet D (75% SPBM) and diet E (100% SPBM; p < 0.05). These results indicate that up to 50% of smoked SPBM can be used for the diet of humpback grouper.

Vascularized proximal fibula epiphyseal transfer for distal radius reconstruction in children: A systematic review.

Reconstruction of the distal radius in children is cumbersome, requiring simultaneous restoration of joint function and axial growth. Vascularized proximal fibular epiphyseal transfers (VFET) have been popularized over non-vascularized transfers and prosthesis. This systematic review aims to evaluate the effectiveness of VFET and its associated complications. Electronic database of PubMed MEDLINE was searched between 1970 and 2014. Studies reporting VFET for distal radius reconstruction in children (<15 years old) with clear reporting of technique (vascular pedicle) and objective outcome measures were included. Outcomes of interest were rate of graft growth, bone union and complications. A one-way Analysis of Variance (ANOVA) test was used to compare growth rates between pedicle types. Fourteen studies met the inclusion criteria, representing 25 patients. Pedicles used were anterior tibial (44%), peroneal (16%), or bi-pedicled (40%) anastomosed in antegrade (64%) or reverse flow (36%) fashion. Among all pedicle types, best results were achieved using anterior tibial artery with reversed flow, yielding average growth rate of 0.83 cm/year (P = 0.01). Recipient complications included four premature epiphyseal plate closures, a flap loss, and six wrist radial deviations. Donor complications included six common peroneal nerve palsies (five temporary, a permanent), and a talocalcaneal instability. Overall complication rates between pedicle types were comparable (P = 0.062). VFET may be a surgical option capable of restoring joint function and axial growth potential in select patients. The reverse flow technique based on the anterior tibial artery may result in superior outcomes. However, the overall complication rate is high and permanent peroneal nerve palsy may result. IV © 2015 Wiley Periodicals, Inc. Microsurgery 36:705-711, 2016.

Statistical characterization of the growth and spatial scales of the substorm onset arc.

We present the first multievent study of the spatial and temporal structuring of the aurora to provide statistical evidence of the near‐Earth plasma instability which causes the substorm onset arc. Using data from ground‐based auroral imagers, we study repeatable signatures of along‐arc auroral beads, which are thought to represent the ionospheric projection of magnetospheric instability in the near‐Earth plasma sheet. We show that the growth and spatial scales of these wave‐like fluctuations are similar across multiple events, indicating that each sudden auroral brightening has a common explanation. We find statistically that growth rates for auroral beads peak at low wave number with the most unstable spatial scales mapping to an azimuthal wavelength λ≈ 1700–2500 km in the equatorial magnetosphere at around 9–12 R E. We compare growth rates and spatial scales with a range of theoretical predictions of magnetotail instabilities, including the Cross‐Field Current Instability and the Shear Flow Ballooning Instability. We conclude that, although the Cross‐Field Current instability can generate similar magnitude of growth rates, the range of unstable wave numbers indicates that the Shear Flow Ballooning Instability is the most likely explanation for our observations.

Characterization of multiple isolates from an Alexandrium ostenfeldii bloom in The Netherlands

Alexandrium ostenfeldii is an emerging harmful algal bloom species forming a global threat to coastal marine ecosystems, with consequences for fisheries and shellfish production. The Oosterschelde estuary is a shallow, macrotidal and mesotrophic estuary in the southwest of The Netherlands with large stocks of mussels, oysters, and cockles. These shellfish stocks were threatened by a recent A. ostenfeldii bloom in the Ouwerkerkse Kreek, which is a brackish water creek discharging water into the Oosterschelde. Little is yet known about the characteristics of the A. ostenfeldii population in this creek. We therefore isolated 20 clones during an A. ostenfeldii bloom in 2013, and characterized these clones on their growth and toxin profile in their exponential growth phase. The cyclic imines were identified by comparison of A. ostenfeldii extracts with the retention time and CID spectra of standard solutions, or with published CID spectra. We furthermore assessed the allelochemical potency and phylogeny of a selection of 10–12 clones. Morphology and molecular phylogeny showed that all clones belong to Group 1 of A. ostenfeldii. All clones showed comparable growth rates of on average 0.22±0.03d−1. During exponential growth, they all produced a unique combination of paralytic shellfish poisoning toxins, spirolides and gymnodimines, of which particularly the latter showed a high intra-specific variability, with a 25-fold difference between clones with the lowest and highest cell quota. Furthermore, the selected 12 clones showed high allelopathic potencies with EC50 values based on lysis assays against the cryptophyte Rhodomonas salina between 212 and 525 A. ostenfeldii cellsmL−1. Lytic activities were lower for cell extracts, indicating an important extracellular role of these compounds. A high intra-specific variability may add to the success of genotypically diverse A. ostenfeldii blooms, and make populations resilient to changes in environmental and climatic conditions.

Microstructural characteristics of β precipitates in Zr–1Nb alloy

The β phase precipitates in a Zr–1Nb alloy annealed at 600 °C and 700 °C (below and above the monotectoid temperature, respectively) for 3 h were investigated by transmission electron microscopy. It was found that the uniformly distributed β phase obtained at 600 °C was spherical, with diameter of 30–60 nm, volume fraction of ∼2.5% and Nb content of ∼68 wt.%. However, the β phase obtained at 700 °C was stick-shaped, with ∼100 nm in diameter and ∼300 nm in length, volume fraction of ∼9.8% and Nb content ∼10 wt.%. The distinctions in volume fractions and compositions were consistent with the lever rule of the Zr–Nb phase diagram. The distinction in shapes resulted from the change in the interfacial structure, which depended on the lattice misfit. The orientation relationship between α matrix and stick-shape β precipitates satisfied Burgers' orientation relationship, i.e., (101¯ 0)α//(11¯ 2)β for the broad face, (0001)α//(110)β for the side facet and (112¯ 0)α//(1¯11)β for the edge. The outline of the stick-shaped β precipitates was composed of straight and curved interfaces, and the broad faces and side facets together formed the straight interface, and the edges formed the curved one. As the Nb content of β phase increased, the lattice misfits on broad face and side facet increased and their interfacial structures changed from coherent (obtained at 700 °C) into incoherent (obtained at 600 °C), and the misfits of edge decreased, and their interfacial structures were always incoherent for the two heat treatments. Therefore, the curved interfaces had a higher growth rate than the straight interfaces at 700 °C and stick-like β phase precipitate was formed. While the three planes have a comparable growth rate at 600 °C and spherical β phase precipitate was formed.

Life-history variation among four shallow-water morphotypes of lake trout from Great Bear Lake, Canada

Abstract Phenotypic variation within populations is common in many salmonids, especially when inhabiting northern postglacial systems. We compared life-history traits among four lake trout morphs co-existing in the shallow-waters of Great Bear Lake (Northwest Territories, Canada). Adult growth rate, age- and size-at-maturity, and survival differed among morphs, consistent with their degree of foraging specialization and predictions from foraging theory, e.g., reduced somatic growth and higher reproductive investment in the generalist morph, high growth throughout life in the piscivorous morph, and intermediate life-histories in the more benthic- and pelagic-oriented morphs. Fecundity and egg size also varied among morphs. However unexpected findings also arose, such as comparable immature growth rates among morphs. Other traits, such as a high proportion of resting individuals among all morphs, suggest life-history adaptations to northern latitudes. Longer resting periods are likely needed to obtain enough energy for reproduction, and may also allow greater investment in post-maturation growth. Overall, lake trout from Great Bear Lake demonstrated remarkable longevity and exceptional asymptotic sizes, even for a northern freshwater ecosystem. Our study provides new insights into life-history evolution among lake trout morphs that use different food sources and habitats. In addition, it contributes to our understanding of this complex aquatic ecosystem, which exhibits one of the highest known levels of intraspecific diversity among freshwater fish.

The MazEF Toxin-Antitoxin System Alters the β-Lactam Susceptibility of Staphylococcus aureus.

Toxin-antitoxin (TA) systems are genetic elements of prokaryotes which encode a stable toxin and an unstable antitoxin that can counteract toxicity. TA systems residing on plasmids are often involved in episomal maintenance whereas those on chromosomes can have multiple functions. The opportunistic pathogen Staphylococcus aureus possesses at least four different families of TA systems but their physiological roles are elusive. The chromosomal mazEF system encodes the RNase toxin MazF and the antitoxin MazE. In the light of ambiguity regarding the cleavage activity, we here verify that MazF specifically targets UACAU sequences in S. aureus in vivo. In a native strain background and under non-stress conditions, cleavage was observed in the absence or presence of mazE. Transcripts of spa (staphylococcal protein A) and rsbW (anti-σB factor) were cut, but translational reporter fusions indicated that protein levels of the encoded products were unaffected. Despite a comparable growth rate as the wild-type, an S. aureus mazEF deletion mutant was more susceptible to β-lactam antibiotics, which suggests that further genes, putatively involved in the antibiotic stress response or cell wall synthesis or turnover, are controlled by this TA system.

Juvenile red swamp crayfish growth affected by isolation from their mother

AbstractThe red swamp crayfish (Procambarus clarkii Girard, 1852) which is indigenous to North America, is the most commercially exploited species in astaciculture. Farming profitability depends mainly on crayfish growth rates. Thus research focused on factors affecting growth of crayfish is of high priority in this sector of aquaculture. Growth rate retardation related to social deprivation in crayfish has never been evaluated in crustaceans. The present experiment was carried out in order to compare growth rates of the Stage 3 juvenile red swamp crayfish from two offspring origins: maternal incubation and early separation from the mother. Juveniles were kept in three types of groups composed each by six individual: maternal incubated, early separated, and mix of both of them. Offspring origin significantly affected juvenile crayfish growth rates when maternally incubated individuals grew faster than crayfish from the other two group types. Moreover, the same significant differences were shown in number of moults. The results of the present study provide new insight into crayfish behaviour related to prior social experience of juveniles, but future studies are needed to verify our assumption.

Spatial and temporal variability in growth of southern flounder (Paralichthys lethostigma)

Delineation of stock structure is important for understanding the ecology and management of many fish populations, particularly those with wide-ranging distributions and high levels of harvest. Southern flounder (Paralichthys lethostigma) is a popular commercial and recreational species along the southeast Atlantic coast and Gulf of Mexico, USA. Recent studies have provided genetic and otolith morphology evidence that the Gulf of Mexico and Atlantic Ocean stocks differ. Using age and growth data from four states (Texas, Alabama, South Carolina, and North Carolina) we expanded upon the traditional von Bertalanffy model in order to compare growth rates of putative geographic stocks of southern flounder. We improved the model fitting process by adding a hierarchical Bayesian framework to allow each parameter to vary spatially or temporally as a random effect, as well as log transforming the three model parameters (L∞, K, and t0). Multiple comparisons of parameters showed that growth rates varied (even within states) for females, but less for males. Growth rates were also consistent through time, when long-term data were available. Since within-basin populations are thought to be genetically well-mixed, our results suggest that consistent small-scale environmental conditions (i.e., within estuaries) likely drive growth rates and should be considered when developing broader scale management plans.

Diverse galactooligosaccharides consumption by bifidobacteria: implications of β-galactosidase--LacS operon.

Galactooligosaccharides (GOS) possess prebiotic properties that specifically increase the number of bifidobacteria in the human intestine, thus giving health benefits to the host. Although the bifidogenic effect of GOS has been demonstrated in numerous studies, the utilization of GOS by specific bifidobacteria remains unclear. The goal of our study was to elucidate GOS consumption by specific bifidobacteria and gain insights into the mechanism. First, we examined GOS consumption by 14 bifidobacterial strains belonging to seven different species by comparing growth rate, carbohydrate consumption, and acid production. We then performed a transcription analysis in the case of one strong GOS consumer, Bifidobacterium adolescentis YIT 4011(T), to predict the operon contributing to GOS use. The study indicated the contribution of an operon consisted of LacS symporter and β-galactosidase to bifidobacterial GOS consumption.

Human pericytes isolated from adipose tissue have better differentiation abilities than their mesenchymal stem cell counterparts.

Multi-potent mesenchymal stem/progenitor cells are present in almost all organs and tissues, although their identity remains elusive. Several isolation strategies have been pursued to identify these cells prospectively, leading to the isolation of various cell populations endowed with multi-lineage mesodermal potential. Historically, mesenchymal stem cells (MSCs) were the first cell population to be isolated from the stromal fraction of most connective tissues. These cells are able to differentiate towards various mesodermal lineages and are currently the most studied adult mesodermal progenitors. Recently, the isolation of a subpopulation of microvascular pericytes (PCs) endowed with multi-lineage mesodermal potential has led to the identification of mesenchymal progenitors that reside in a defined anatomical location, namely the wall of small blood vessels. To gain insight into these two related cell populations, we performed a detailed analysis of the mesodermal potential of isogenic human MSCs and PCs isolated from white adipose tissue. Although both cell populations expressed known mesodermal markers at similar levels and displayed a comparable growth rate, PCs differentiated towards osteocytes, adipocytes and myocytes more efficiently than their MSC counterparts, as revealed by both histological and molecular assays. Our results show that microvascular PCs are more prone to mesenchymal differentiation than MSCs and therefore represent a preferable source of human adult mesenchymal progenitors when adipose tissue is used as a cell source.

Longitudinal Cortical Development During Adolescence and Young Adulthood in Autism Spectrum Disorder: Increased Cortical Thinning but Comparable Surface Area Changes

Prior reports suggest that autism spectrum disorder (ASD) is associated with atypically excessive early brain growth. Recent cross-sectional studies suggest that later cortical development during adolescence/adulthood might also be aberrant, although longitudinal designs are required to evaluate atypical growth trajectories. The present study sought to examine longitudinal changes in cortical thickness and surface area among adolescents and young adults with ASD. Two high-resolution anatomic magnetic resonance imaging scans approximately 2 years apart were acquired from 17 adolescents with ASD and 18 typically developing (TD) adolescents, matched on age (range = 14-24 years), IQ, sex ratio, and handedness (70 scans total). The FreeSurfer image analysis suite was used to quantify longitudinal changes in cortical thickness and surface area. Accelerated cortical thinning for the ASD group as compared to the TD group was found in 2 areas in the left hemisphere, the posterior portion of ventral temporal cortex and superior parietal cortex (cluster corrected p < .01). For ventral temporal cortex, cortical thinning was associated with everyday executive function impairments, and thinner cortex at time 2 was correlated with ASD social symptoms. Differences in surface area changes were not detected. The present longitudinal study extends prior cross-sectional research by demonstrating increased cortical thinning (in portions of temporal and parietal cortex) but comparable surface area growth rates in participants with ASD compared to TD controls during adolescence and into young adulthood. These findings provide further evidence for atypical cortical development beyond the early years in ASD, marked by increased cortical thinning in late adolescence/young adulthood.

Emergency Department and Inpatient Hospital Use by Medicare Beneficiaries in Patient-Centered Medical Homes

Patient-centered medical homes are primary care practices that focus on coordinating acute and preventive care. Such practices can obtain patient-centered medical home recognition from the National Committee for Quality Assurance. We compare growth rates for emergency department (ED) use and costs of ED visits and hospitalizations (all-cause and ambulatory-care-sensitive conditions) between patient-centered medical homes recognized in 2009 or 2010 and practices without recognition. We studied a sample of US primary care practices and federally qualified health centers: 308 with and 1,906 without patient-centered medical home recognition, using fiscal year 2008 to 2010 Medicare fee-for-service data. We assessed average annual practice-level payments per beneficiary for ED visits and hospitalizations and rates of ED visits and hospitalizations (overall and ambulatory-care-sensitive condition) per 100 beneficiaries before and after patient-centered medical home recognition, using a difference-in-differences regression model comparing patient-centered medical homes and propensity-matched non-patient-centered medical homes. Comparing patient-centered medical home with non-patient-centered medical home practices, the rate of growth in ED payments per beneficiary was $54 less for 2009 patient-centered medical homes and $48 less for 2010 patient-centered medical homes relative to non-patient-centered medical home practices. The rate of growth in all-cause and ambulatory-care-sensitive condition ED visits per 100 beneficiaries was 13 and 8 visits fewer for 2009 patient-centered medical homes and 12 and 7 visits fewer for 2010 patient-centered medical homes, respectively. There was no hospitalization effect. From 2008 to 2010, outpatient ED visits increased more slowly for Medicare patients being treated by patient-centered medical home practices than comparison non-patient-centered medical homes. The reduction was in visits for both ambulatory-care-sensitive and non-ambulatory-care-sensitive conditions, suggesting that steps taken by practices to attain patient-centered medical home recognition such as improving care access may decrease some of the demand for outpatient ED care.

Coral Growth Assessment on an Established Artificial Reef in Antigua

Anthropogenic pressure on coral reef ecosystems has increased the need for effective restoration and rehabilitation as a management tool. However, quantifying the success of restoration projects can be difficult, and adequate monitoring data are scarce. This study compared growth rates over a six-year period of three Caribbean coral species, staghorn coral ( Acropora cervicornis ), elkhorn coral ( Acropora palmata ), and thick finger coral ( Porites porites ), transplanted on an artificial reef off Maiden Island, Antigua, to literature values for the same species growing on naturally formed reefs in the Caribbean region. The average growth rate of staghorn coral was considerably lower than growth rates reported in the literature, while elkhorn and finger corals showed growth rates similar to literature values. The observed inter- and intraspecific differences may be caused by species-specific growth requirements and/or restoration site conditions, factors that should be taken into account when planning future projects involving coral transplant or rescue. This study also determined the analytical precision of a ‘low tech’ monitoring method using a basic underwater digital camera and the software program ImageJ to measure growth rates of corals. Measurement error between volunteer analysts receiving only minimal training was shown to be very small, ranging from 0.37–1.40% depending on the coral species. This confirms the validity of this basic technique, particularly in cases where data are sparse and resources for monitoring are extremely limited.

Bacterial Growth and Shape Regulation by External Compression

Gram-negative Escherichia coli are rod-shaped and maintain a constant diameter during their exponential growth phase. This shape has been shown to be critical in regulating many fundamental biological functions including nutrient access, cell division, attachment, dispersal, and motility. Here, we experimentally show that mechanical forces regulate growth and shapes of E. coli. By applying precisely controllable compressive forces to growing rod-shaped E. coli, we demonstrate that the cells no longer retain their rod shapes but grow and divide with pancake-like shapes while these deformed cells can recover their shapes in several generations after the forces are removed. Those cells are proved to have comparable growth rate, proliferation rate, DNA replication, and protein synthesis to rod-shaped cells. Furthermore, the growth of compressed cells also helps reveal the biological and mechanical role of MreB in maintaining cell shape.