An important principle of science is that experiments or studies should be reproducible by someone working independently.  In order for this to occur, data that is the basis of research findings must be available.  Explicit statements of data deposit requirements from some major scientific journals are included below to illustrate this expectation.

Dryad

Dryad is an international repository of data underlying peer-reviewed articles in the basic and applied biosciences. Dryad enables scientists to validate published findings, explore new analysis methodologies, repurpose data for research questions unanticipated by the original authors, and perform synthetic studies. Dryad is governed by academic and research institutions, research funders, scholarly societies and publishers that collaboratively promote data archiving and ensure the sustainability of the repository.

Journal of the Royal Society Interface

The Open Data Policy section of Author guidelines states that "to allow others to verify and build on the work published in Royal Society journals, it is a condition of publication that authors make available the data, code and research materials supporting the results in the article." 

Nature

A condition of publication in a Nature journal is that authors are required to make materials, data and associated protocols promptly available to others without undue qualifications. Data sets must be made freely available to readers from the date of publication, and must be provided to editors and peer-reviewers at submission, for the purposes of evaluating the manuscript.

Nature includes examples of appropriate public data repositories.

PLoS

PLoS Editorial and Publishing Policy states that "PLOS is committed to ensuring the availability of data and materials that underpin any articles published in PLOS journals. PLOS's ideal is to make all data relevant to a given article and all readily replaceable materials immediately available without restrictions (while not compromising confidentiality in the context of human-subject research)." 

PNAS

Proceedings of the National Academy of Sciences of the United States of America (PNAS) states that "to allow others to replicate and build on work published in PNAS, authors must make materials, data, and associated protocols available to readers."

Science

Data Standards of Science - All data used in the analysis must be available to any researcher for purposes of reproducing or extending the analysis. Data must be available in the paper or deposited in a community special-purpose repository or a general-purpose repository such as Dryad. A list of approved databases is provided in the Data and Code Deposition section of the Editorial Policies.

National Academies Press 

The National Academies Press (NAP) publishes reports issued by the National Academy of Sciences, the National Academy of Engineering, the National Academy of Medicine, and the National Research Council, all operating under a charter granted by the Congress of the United States. Their landmark book Sharing Publication-Related Data and Materials: Responsibilities of Authorship in the Life Sciences is available in full text online.